Patent Publication Number: US-2023134014-A1

Title: Intraocular lens device and related methods

Description:
INCORPORATION BY REFERENCE TO ANY PRIORITY APPLICATIONS 
     Any and all applications for which a foreign or domestic priority claim is identified in the Application Data Sheet as filed with the present application are hereby incorporated by reference under 37 CFR § 1.57. This is a divisional application of U.S. application Ser. No. 16/434,026, filed on Jun. 6, 2019, which claims the benefit of U.S. Provisional Application No. 62/682,037, filed on Jun. 7, 2018, each of which are hereby incorporated herein by reference in their entireties under 37 CFR 1.57. In addition, this application incorporates by reference the entirety of each of the following patent applications: U.S. application Ser. No. 15/144,544 filed on May 2, 2016, issued as U.S. Pat. No. 10,159,564; U.S. application Ser. No. 14/447,621 filed on Jul. 31, 2014, issued as U.S. Pat. No. 10,004,596; and International Application No. PCT/US2016/064491 filed on Dec. 1, 2016 and published as WO 2017/096087. 
    
    
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     This application relates to an intraocular device configured to be placed in a capsular bag of a human eye following a capsulotomy to hold the capsular bag open and to provide a cavity in which an accommodating intraocular device can be placed, and to systems and methods for implanting the same. 
     Description of the Related Art 
     Surgical procedures on the eye have been on the rise as technological advances permit for sophisticated interventions to address a wide variety of ophthalmic conditions. Patient acceptance has increased over the last twenty years as such procedures have proven to be generally safe and to produce results that significantly improve patient quality of life. 
     Cataract surgery remains one of the most common surgical procedures, with over 28 million cataract procedures being performed worldwide per year. It is expected that this number will continue to increase as average life expectancies continue to rise. Cataracts are typically treated by removing the crystalline lens from the eye and implanting an intraocular lens (“IOL”) in its place. As conventional IOL devices are designed to provide clear distance visions, they fail to correct for presbyopia. As a result, reading glasses are still required. Thus, although the vision of patients who undergo a standard IOL implantation will not be clouded by the cataract, they are unable change focus from far to near. 
     Furthermore, it is unfortunately common for the IOL to settle into a position other than what was expected or planned prior to or during the surgery. Even if intraoperative measurements are made to confirm the optics during the procedure, the position of the IOL can change following surgery due to a number of processes. For instance, traditional IOLs are low volume structures optimized for insertion through small incisions. As such traditional IOLs are thin in the anterior-posterior direction, allowing anterior and posterior aspects of the capsular bag to come together. When adjacent layers of the anterior and posterior aspects of capsular bag contact, a process called fibrosis occurs, which can change the IOL position or orientation and/or can lead to posterior capsular opacification. 
     SUMMARY OF THE INVENTION 
     Accordingly, there is a need for an intraocular device that can be placed in the capsular bag following capsulotomy and can provide enhanced outcomes for patient. Enhanced outcomes can be in a variety of forms. For instance accommodating IOL device can be assembled in the eye, which device can have the ability to change the power of the eye for focusing on near, far, and in-between. Another enhanced outcome made possible by the devices and methods disclosed herein is the ability to select a lens that corrects astigmatism and other higher order aberrations. The devices and method disclosed herein are uniquely configured to assure rotational position of the aberration correcting optic. A further enhanced outcome made possible by the devices and methods disclosed herein is providing assurances of proper lens positioning in surgery and thereafter. This is made possible by the configuration of a base member which is positioned in the eye during the surgery in a manner that reduce, minimizes, or eliminates posterior-anterior drift following placement so that the patient&#39;s vision is substantially unchanged following the surgery. 
     In various embodiments, a base member for an accommodating intraocular lens device is provided. The base member includes a base lens and a haptic. The haptic includes a first open end, a second end coupled with the base lens, and an outer periphery configured to engage an equatorial region of a capsular bag. The haptic further comprises an inner periphery and a height between a first edge and a second edge. The inner periphery is disposed about a cavity and having a lens retention portion configured to receive and retain a power changing lens. 
     In some embodiments, a portion of the haptic anterior to the lens retention portion of the cavity can comprise enhanced flexibility compared to the lens retention portion. In some other embodiments, a portion of the haptic disposed about the lens retention portion of the cavity can comprise enhanced stiffness compared to the lens retention portion. The haptic can comprise a plurality of compression members. Each compression member can comprise a circumferentially extending contact zone, a first radial force member coupled with a first circumferential end and a second radial force member coupled with a second circumferential end of each contact z one. 
     Various embodiments of the accommodating intraocular lens device can further comprise a compression member hinge disposed between each first radial force member and each second radial force member. The compression member hinge can comprise a groove disposed in the outer periphery of the haptic. The groove can comprise an anterior portion that extends entirely from the outer periphery to the inner surface of the haptic and a posterior portion that is enclosed by the contact zone. The anterior portion can extend about 35% of the height of the haptic from the first open end. The anterior portion of the compression member hinge can be more circumferentially deformable than the posterior portion. 
     Various embodiments of the accommodating intraocular lens device can comprise a plurality of contact zones, each contact zone disposed between adjacent internal hinges formed in the inner surface of the haptic. Various embodiments of the accommodating intraocular lens device can further comprise a plurality of external hinges disposed about the outer periphery of the haptic. The external hinges can be spaced circumferentially from the internal hinges. The external hinges can comprise a groove extending radially inwardly from the outer periphery. The internal hinges can comprise a groove extending radially outwardly from the inner surface. The radially inner-most edge of the grooves of the external hinges can be radially inward of the radially outer-most edge of the grooves of the internal hinges. 
     Various embodiments of the accommodating intraocular lens device can comprise a plurality of contact zones. Alternating contact zones can be spaced apart from and not coupled with the base lens radially inwardly thereof. Various embodiments of the accommodating intraocular lens device can further comprise a plurality of spaced apart radial hinges comprising a first portion coupled with the base lens and a second portion coupled with the haptic. In various embodiments of the accommodating intraocular lens device, the second end of the haptic can comprise a ring and a hinge having a first end coupled to the ring and a second end coupled to the inner surface of the haptic. 
     In various embodiments of the accommodating intraocular lens device, the base lens can comprise a haptic interface surface and the ring of the haptic can comprise a lens interface surface. The haptic interface surface of the base lens can be coupled to the lens interface surface of the ring of the haptic. The haptic can comprise a first material configured to transfer force between outer periphery and the inner surface and the base lens can comprise a second material different from the first material. The lens retention portion can comprise a retention member comprising an anterior surface having a ridge formed thereon on an anterior side thereof. The ridge can be visible during implantation to enable a visual confirmation of proper placement of a power changing lens posterior to the retention member. 
     Various embodiments of an accommodating IOL can comprise the accommodating intraocular lens device described herein and a power changing lens configured to fit within the cavity. The power lens can comprise a first side, a second side, a peripheral portion coupling the first and second sides, and a closed cavity configured to house a fluid. The first side of the power changing lens can be spaced from the first edge of the haptic. In various embodiments, at least a portion of the haptic can comprise a material with high contrast to the material of the peripheral portion of the power changing lens. In some embodiments, at least a portion of the haptic can comprise an at least partially opaque dye and the peripheral portion of the power changing lens is translucent. In some other embodiments, at least a portion of the haptic can comprise a first color surface and the peripheral portion of the power changing lens can comprise a second color surface visually distinct from the first color surface. In some embodiments, at least a portion of the haptic can comprise a first visual pattern and the peripheral portion of the power changing lens can comprise a second visual pattern visually distinct from the first visual pattern. 
     Various embodiments of the accommodating IOL can comprise a plurality of open channels extending from outside of the accommodating IOL to a space between the base lens and the second side of the power changing lens. In some embodiments of the accommodating IOL, the haptic can comprise a plurality of spaced apart radial hinges comprising a first portion coupled with the base lens and a second portion coupled with the haptic, a gap provided between the radial hinges and the second side of the power changing lens when the accommodating intraocular lens is in an accommodated state and when the accommodating intraocular lens is in a disaccommodated state. 
     In another embodiment, a method of assembling an intraocular lens in a capsular bag of an eye of a patient is provided. An injector barrel is advanced into the eye of the patient. The injector barrel contains a base member. The base member has a base lens and a ring-shaped member coupled to the base lens. In various embodiments, the ring-shaped member can be configured as a haptic. The ring-shaped member has a first edge located at an open end thereof. The first edge is disposed about an anterior end of a cavity. The base lens is coupled with a second edge of the ring-shaped member. The base member is folded about a transverse axis of the base lens or of a portion of the ring-shaped member or the haptic such that the cavity is on a concave side of the transverse axis and the base lens is on a convex side of the transverse axis. The injector barrel is oriented such that the concave side of the base member fold is oriented anteriorly relative to the patient&#39;s eye. The base member is advanced out of the injector barrel such that the base member unfolds with the base lens facing posteriorly toward the posterior surface of the capsular bag and the cavity facing anteriorly toward the cornea. A power changing lens is advanced into the cavity of the base member within the capsular bag of the eye of the patient. The power changing lens has an anterior surface, a posterior surface, and a circumferential portion disposed between the anterior surface and the posterior surface. The power changing lens is folded about a transverse axis of the power changing lens. The power changing lens is unfolded within the cavity of the base member such that the circumferential portion of the power changing lens engages a side of the ring-shaped member facing the cavity. 
     In one variation the posterior surface of the power changing lens is disposed on a concave side of a power changing lens fold (e.g., concave side of the transverse axis of power changing lens) and the anterior surface is disposed on a convex side of the power changing lens fold (e.g., concave side of the transverse axis of power changing lens). The power changing lens is oriented such that the concave side of the power changing lens fold faces posteriorly prior to unfolding. 
     In another variation, the power changing lens is folded such that the posterior surface is disposed on a convex side of a power changing lens fold and a deformable membrane on the anterior surface is disposed on a concave side of the power changing lens fold further comprising orienting the power changing lens such that the concave side of the folded power changing lens faces anteriorly. 
     In another embodiment, a method of assembling an intraocular lens in a capsular bag of an eye of a patient is provided. A bowl-shaped member is positioned in a capsular bag of an eye with a base lens of the bowl shaped member contacting a posterior inside surface of the capsular bag. A haptic contacts an equatorial region of the capsular bag. The haptic has a first edge disposed forward of an anterior surface of the base lens. The bowl-shaped member defines a cavity therein. A power changing lens is advanced into the cavity of the bowl shaped member in a folded state wherein opposing sides of a circumferential portion of the power changing lens are brought together. The power changing lens is unfolded within the cavity of the bowl-shaped base member such that the circumferential portion of the power changing lens is retained within the haptic. 
     In one variation, the power changing lens is unfolded while the concave side of the fold faces posteriorly. In another variation, a deformable membrane of the power changing lens faces a concave side of the fold, wherein the fold faces anteriorly. 
     An innovative aspect of the subject matter of this application is embodied in an ophthalmic lens system, comprising an injector comprising a plunger and a barrel having a lumen extending proximally from a distal end along a longitudinal axis; a base member comprising a base lens and a ring-shaped member coupled to the base lens, the ring-shaped member comprising a first edge defining an open end of the base member, the base lens being coupled with a second edge of the ring-shaped member, the base member being folded and disposed in the lumen of the barrel of the injector such that the base lens is adjacent to the lumen and the cavity is disposed between the base lens and the longitudinal axis of the lumen; and a power changing lens comprising an anterior surface, and a posterior surface coupled with the anterior surface, the power changing lens being folded such a circumferential portion disposed between the posterior surface and the anterior surface is brought together. The power changing lens is disposed in the lumen of the barrel proximal to the base member. 
     In various embodiments of the ophthalmic lens system, the base lens and the anterior surface can be disposed on opposite sides of the lumen of the barrel of the injector. The anterior surface of the power changing lens can comprise a flexible membrane and the posterior surface of the power changing lens can comprise a surface of powered lens. A fluid can be contained between the anterior surface of the power changing lens and posterior surface of the power changing lens. The power changing lens and the base member can be separated from and not connected to each other. The anterior surface can be disposed adjacent to the lumen and the posterior surface can be disposed between the anterior surface and the longitudinal axis of the lumen. The posterior surface can be disposed adjacent to the lumen and the anterior surface is disposed between the posterior surface and the longitudinal axis of the lumen. 
     In some embodiments an intraocular lens component is provided that includes an anterior side, a posterior side, a peripheral portion and a visible color structure. The anterior side has an anterior optical surface disposed across an optical axis of the lens component. The posterior side has a posterior optical surface disposed across the optical axis. The peripheral portion has an anterior portion coupled to the anterior side and a posterior portion coupled to the posterior side. The peripheral portion couples the anterior side to the posterior side of the intraocular lens component. The visible color structure is disposed in the peripheral portion between the anterior portion and the posterior portion thereof. 
     In another embodiment, an intraocular lens component is provided that includes an anterior side, a posterior side, a peripheral portion and a rotational position feature. The anterior side has an anterior optical surface disposed across an optical axis of the lens component. The posterior side has a posterior optical surface disposed across the optical axis. The peripheral portion has an anterior portion coupled to the anterior side and a posterior portion coupled to the posterior side. The peripheral portion couples the anterior side to the posterior side of the intraocular lens component. The rotational position feature is disposed on or in the peripheral portion and is configured to provide simultaneous confirmation of orientation about at least two axes. 
     In another embodiment a method of assembling a base member of an intraocular lens is provided. The base member haptic is provided. The base member haptic has a first open end, a second end opposite the first open end, and an outer periphery configured to engage an equatorial region of a capsular bag. The second end has a lens interface portion. A base lens a central optical portion and a peripheral haptic interface portion is provided. The haptic interface portion of the base lens is coupled with the lens interface portion of the base member haptic. The base lens and the base member haptic are secured together at the lens interface portion and the haptic interface portion. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other features, aspects and advantages are described below with reference to the drawings, which are intended for illustrative purposes and should in no way be interpreted as limiting the scope of the embodiments. Furthermore, various features of different disclosed embodiments can be combined to form additional embodiments, which are part of this disclosure. In the drawings, like reference characters denote corresponding features consistently throughout similar embodiments. The following is a brief description of each of the drawings. 
         FIG.  1    shows an anterior perspective, broken out view of an eye with an accommodating intraocular lens (IOL) device according to one embodiment of the present disclosure disposed therein; 
         FIG.  2    is an anterior perspective view of the accommodating IOL device shown in  FIG.  1   ; 
         FIG.  2 A  and  FIG.  2 A- 1    are anterior views of the accommodating IOL device of  FIG.  2   ; 
         FIG.  2 B  is an exploded view of the accommodating IOL device of  FIG.  2   ; 
         FIG.  2 C  is a cross-sectional view of the accommodating IOL device of  FIG.  2    taken at section plane  2 - 2 C; 
         FIG.  2 D  is a cross-sectional view of the accommodating IOL device of  FIG.  2    taken at section plane  2 D- 2 D; 
         FIG.  3 A  is an anterior perspective view of a base member of an ophthalmic device, such as the accommodating IOL device of  FIG.  2   ; 
         FIG.  3 B  is an anterior view of the base member of  FIG.  3 A ; 
         FIG.  3 C  is a cross-section view of the base member of  FIG.  3 A  taken at section plane  3 C- 3 C in  FIG.  3 B ; 
         FIG.  4 A  is a perspective view of a power changing lens of the accommodating IOL of  FIG.  2   ; 
         FIG.  4 B  is a cross-sectional view of the power changing lens of  FIG.  4 A  taken at section plane  4 B- 4 B; 
         FIG.  4 C  is an anterior view of the power changing lens of  FIG.  4 A  with a rotational position feature indicating simultaneous visual confirmation of orientation. 
         FIG.  4 D  is a posterior view of the power changing lens of  FIG.  4 C . 
         FIG.  4 E  is an anterior perspective view of a non-accommodating lens. 
         FIG.  4 F  is an anterior perspective view of an extended depth of focus (EDOF)/trifocal lens. 
         FIG.  5    is a detail view of a portion of the base member of  FIG.  3    at detail  5 - 5  in  FIG.  3 B ; 
         FIG.  5 A  is a cross-section at section plane  5 A- 5 A in the detail view of  FIG.  5   ; 
         FIG.  6    is a detail view of a portion of the base member of  FIG.  3    at detail  6 - 6  in  FIG.  3 B ; 
         FIG.  6 A  is a cross-section at section plane  6 A- 6 A in the detail view of  FIG.  6   ; 
         FIG.  7    is a detail view of a portion of the base member of  FIG.  3    at detail  7 - 7  in  FIG.  3 B ; 
         FIG.  7 A  is a cross-section at section plane  7 A- 7 A in the detail view of  FIG.  7   ; 
         FIG.  8    is an anterior view similar to that of  FIG.  3 B  showing a modified embodiment of a retention member aiding a surgeon assembling an accommodating IOL similar to that of  FIG.  1    in the eye; 
         FIG.  8 A  is a cross-section at section plane  8 A- 8 A in the detail view of  FIG.  8   ; 
         FIG.  8 B  and  FIG.  8 C  show the visual indication provided by the modified embodiment of a retention member to aid a surgeon in correctly assembling the accommodating IOL similar to that of  FIG.  1    in the eye; 
         FIG.  9    is a top view similar to that of  FIG.  3 B  showing a modified embodiment of a ring member visually aiding a surgeon assembling an accommodating IOL similar to that of  FIG.  1    in the eye; 
         FIG.  10 A  schematically illustrates an unaltered human eye, which may be in need of cataract or presbyopia treatment surgery; 
         FIG.  10 B  schematically illustrates the human eye following removal of the contents of the crystalline lens, leaving the capsular bag intact; 
         FIG.  10 C  shows delivery of a base member lens into the eye following removal of the crystalline lens, the base member being folded during delivery; 
         FIG.  10 D  shows the base member being un-folded within the capsular bag; 
         FIG.  10 E  shows the base member completely unfolded within the capsular bag; 
         FIG.  10 F  shows a power changing lens being delivered into the eye through the same incision used to deliver the base member in  FIG.  10 C ; 
         FIG.  10 E- 1    schematically shows a first approach for delivering a power changing lens opposite to a retention member of the base member of  FIG.  3   ; 
         FIG.  10 E- 2    schematically shows a second approach for delivering a power changing lens opposite to a retention member of the base member of  FIG.  3 A ; 
         FIG.  10 G  shows the power changing lens according to the first approach being advanced out of an injector barrel into the base member; 
         FIG.  10 H  shows the power changing lens in the process of being unfolded and disposed under the retention members of the base member of  FIG.  3 A ; 
         FIG.  10 I  shows the power changing lens, with the rotational position feature of  FIG.  4 C , under the retention members of the base member of  FIG.  3 A ; and 
         FIG.  11    shows a system including an injector having a base member disposed in a distal portion thereof and a power changing lens disposed in a proximal portion thereof. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     This application discloses a base member  102  for a multi-component IOL device  100 . The components of the IOL device are maintained separate until being assembled within an eye  50  of the patient. Once assembled, the IOL device  100  can provide premium lens performance. In a first embodiment, discussed in S ECTION  I, the IOL device  100  is configured to provide accommodation when subject to ocular forces and thus will be referred to herein as an accommodating IOL device  100 . Various embodiments of the IOL device  100  can be configured to correct for a higher order aberration, such as astigmatism, with or without additionally providing accommodation. Furthermore, various embodiments of the IOL device  100  can be configured to provide post-surgical emmetropia, with or without accommodation, using the base member as a volume restoring member. 
     I. Accommodating IOL Device Embodiments 
     Providing clear focus over distances from near to far is one of the chief aims of surgery in the front part of the eye. An accommodating IOL device  100  described herein in various embodiments is uniquely configured for this objective. 
     A. Eye Anatomy and Accommodation 
       FIG.  1    shows an eye  50  following placement of the accommodating IOL device  100 . The natural lens of the eye  50  has been modified by a capsulotomy procedure in which an opening  58  is formed in the natural crystalline lens the capsular bag  62  is evacuated of its contents through the opening  58 . The opening  58  provides access through an access pathway from an exterior of the eye  50  for placement of the accommodating IOL device  100  in the capsular bag  62 . 
     An equatorial region  74  of the capsular bag  62  is coupled by zonules  66  to a ciliary muscle  70 . The zonules  66  are connective tissues that can stretch the capsular bag  62 . When the ciliary muscle  70  is in a rest state the zonules  66  are stretched and apply a tension force to the capsular bag  62 . When the eye  50  attempts to accommodate, the ciliary muscle  70  contracts, reducing the tension in the zonules  66 . These accommodation processes result in a compression force on the base member  102  as discussed further below. Without being bound to a particular theory, it is believed that the capsular bag  62  contracts when the tension in the zonules  66  is reduced. That contraction applies a compression force the base member  102  to cause accommodation of a power changing lens  104  that can be placed in the base member  102 . The ocular forces of the eye  50  are sufficient to change the shape of one or more optical surface of the power changing lens  104 , resulting in accommodation. 
     B. Separate Component Accommodating IOL Structure 
       FIGS.  2 - 2 D  show variants of the accommodating IOL device  100  shown in  FIGS.  1  and  10 C -H assembled separate from the eye  50 . The accommodating IOL device  100  includes a base member  102  and a power changing lens  104 . The power changing lens  104  is separate from the base member  102  such that the base member  102  and the power changing lens  104  can be delivered separately, e.g., sequentially. The variants illustrated by  FIGS.  2 - 9    can provide a lower position for the power changing lens  104  than those of  FIGS.  1  and  10 C -H. The discussion in  FIGS.  1  and  10 C -H also apply to the variants of  FIGS.  2 - 9   . The systems of  FIG.  11    apply to all variants herein. The base member  102  can be delivered before the power changing lens  104 . The power changing lens  104  can be subsequently delivered into the base member  102  and can be unfolded within the base member  102  when the base member  102  is in the capsular bag  62  of an eye  50 . This sequential delivery allows the base member  102  and the power changing lens  104  to have more complex structure, providing premium function and yet still be deliverable through a small incision. 
     The base member  102  can include a base lens  120  and a haptic  124 . The base lens  120 , if present, provides some of the focusing power of the accommodating IOL device  100 . The haptic  124  extends into the equatorial region  74  of the capsular bag  62  and establishes a mounting position for the power changing lens  104 . In one embodiment the base lens  120  and the haptic  124  cooperate to maintain the capsular bag  62  in an expanded state, similar to the shape and size of the crystalline lens  54  prior to the capsulotomy. As such, the base member  102  is large compared to traditional non-premium IOLs which are designed for delivery through a small incision. 
     The power changing lens  104  includes multiple optical components, e.g., a membrane at a first side  400  and a lens at a second side  404 . An optical fluid can be disposed between the first side  400  and the second side  404  The power changing lens  104  includes a peripheral portion  408  that together with the optical components at the first side  400  and second side  404  contain the optical fluid. The optical fluid has a number of advantages, including transferring compressive forces from the peripheral portion  408  of the power changing lens  104  to the deformable optical surfaces in a controlled manner to provide optically acceptable surfaces across the range of accommodation. The structure of the power changing lens  104  is much more complex than a traditional non-premium IOL, to provide premium function. 
     Separating the base member  102  and the power changing lens  104  prior to insertion into the eye enables a smaller incision size than were all the optical components inserted simultaneously as unit. The base member  102  and the power changing lens  104  can be compressed to a greater extent when separate than when they are combined into an assembly. Additionally, forming the base member  102  separate from the power changing lens  104  enables the base member  102  to be used in other IOL devices that may not necessarily be accommodating. 
       FIG.  2 A  shows that the accommodating IOL device  100  can have one or a plurality of open channels  108  when assembled. The open channels  108  extend in an anterior and posterior direction between a posterior side of the base member  102  and an anterior side of the power changing lens  104 . There are twelve open channels  108  in the illustrated embodiment. There can be more or fewer open channels  108 , e.g., at least two, at least four, at least six, at least eight, or at least ten open channels  108 . Preferably there are an even number of channels arranged symmetrically relative to an optical axis A of the IOL device  100 . Each of the open channels  108  is defined in part by an inner periphery  144  of the base member  102  and by the outer periphery or outer peripheral portion  408  of the power changing lens  104 . The open channels  108  can each be disposed between adjacent compression arms  180  of the base member  102 , which are discussed further below. The open channels  108  allow fluid to circulate in the capsular bag  62 , e.g., to flow between anterior and posterior sides of the device  100  and to flow from areas outside the optical zone of the accommodating IOL device  100  to within the optical zone. This fluid flow can reduce the tendency of the accommodating IOL device  100  to create pressurized zones between the capsular bag  62  and the surfaces of the components of the device  100 . 
       FIG.  2 C  shows the accommodating IOL device  100  can have one or a plurality of open channels  109  when assembled that can also provide for flow from outside the accommodating IOL device  100  into a space  112  disposed between the base member  102  and the power changing lens  104 .  FIG.  2 C  shows fluid flow  110  that can be provided through the open channels  109 . As discussed further below, the channels  109  are configured to permit fluid flow but to restrict migration of cells into the space  112 . The channels  108  are provided in a posterior-anterior direction to provide or enhance flow  110  between the anterior and posterior sides of the accommodating IOL device  100  as shown in  FIGS.  2  and  2 A . The plurality of open channels  109  can allow fluid to flow from outside the accommodating IOL device  100  to a location between the base lens  120 , if present, and the second side  404  of the power changing lens  104 . By opening the space  112  to flow of fluid from outside the accommodating IOL device  100  to a location between the base lens  120  and the second side  404 , the application of force in a direction transverse to the optical axis OA rather than along the optical axis OA is the primary cause of power change. The transfer of forces from the equatorial region  74  through the base member  102  to the power changing lens  104  can be uniquely configured to cause accommodation upon uniformly dispersed radial and circumferential compression. 
       FIGS.  2 B,  3 A,  10 D- 10 F and  10 G- 10 H  show that the base member  102  has a cavity  160  configured to receive and retain the power changing lens  104 . The cavity  160  is defined between the base lens  120  and an opening  136  at an opposite end of the base member  102  and is surrounded by a haptic  124  disposed at a periphery of the accommodating IOL device  100 . More specifically, the base lens  120  includes an anterior surface  122  that faces the cavity  160 . The anterior surface  122  partly bounds the cavity  160 . The base lens  120  also has a posterior surface  123  that faces toward and may contact an anterior side of the posterior portion of the capsular bag  62 . In some embodiments, a curvature of the anterior surface  122  can be lesser than a curvature of posterior surface  123 . For example, the curvature of the anterior surface  122  can be less than or equal to about 15 mm −1 . The curvature of the anterior surface  122  can be greater than 0 and less than or equal to about 12 mm −1 , greater than 0 and less than or equal to about 10 mm −1 , greater than 0 and less than or equal to about 7 mm −1 , greater than 0 and less than or equal to about 5 mm −1 , greater than 0 and less than or equal to about 3 mm −1 , or any value in a range/sub-range defined by any of these values. As another example, the base lens  120  can be configured as a plano-convex lens having a substantially planar anterior surface  122 . In such embodiments, the curvature of the anterior surface  122  can be 0 or substantially equal to 0 (e.g., less than or equal to 0.1 mm −1 . Also, the haptic  124  has a first end  128  and a second end  132  opposite the first end  128 . The first end  128  is the end of the haptic  124  that is anterior when the base member  102  is placed in the capsular bag  62 . The second end  132  is the end of the haptic  124  that is posterior to the first end  128  when the base member  102  is placed in the capsular bag  62 . The cavity  160  is disposed between a first edge  152  and a second edge of the haptic  124 . As discussed further below, the haptic  124  has anterior and posterior zones disposed about the cavity  160  that are separately configured for retention and compression of the power changing lens  104  and for enhancing overall compressibility of the base member  102 . 
       FIG.  2    shows the power changing lens  104  is inset in the cavity  160 . As discussed herein, this state can be achieved in the eye in order to reduce or minimize incision size. A first side  400  of the power changing lens  104  is posterior to an opening  136  of the haptic  124  formed at the first end  128  thereof. The configuration of the haptic  124  of the base member  102  assures that the posterior side of the anterior portion of the capsular bag  62  remains spaced away from the posterior portion of the capsular bag  62 . The spacing of the two layers of the capsular bag  62  from each other reduces, minimizes, or eliminates fibrosis between these structures which would limit or reduce the potential for accommodative amplitude. A height  148  of the haptic  124  (see  FIG.  5 A ) between a first edge and a second edge of it outer periphery is configured to retain the capsular bag  62  in an open configuration. For example, the height  148  of the haptic  124  can be greater than or equal to about 2 mm. In various embodiments, the height  148  of the haptic  124  can be greater than or equal to about 2.0 mm and less than or equal to about 3.5 mm, greater than or equal to about 2.2 mm and less than or equal to about 3.3 mm, greater than or equal to about 2.5 mm and less than or equal to about 3.0 mm, or any height in a range/sub-range defined by any of these values. The height  148  and profile of the outer periphery  140  are configured to keep anterior portions of the capsular bag  62  anterior of posterior portions of the capsular bag  62 . This can reduce, eliminate or minimize fibrosis or “shrink-wrapping” of the capsular bag  62 . The height  148  and profile of the outer periphery  140  are configured to keep anterior portions of the capsular bag  62  anterior of the power changing lens  104 . This can prevent the capsular bag  62  from interfering with the accommodating performance of the accommodating IOL device  100 , as discussed further below. In various embodiments, the haptic  124  can comprise an opaque dye (e.g., dark blue dye, indigo dye, violet dye) to increase the visibility of the haptic during implantation of the power changing lens. 
     The distance from the opening  136  to the first side  400  of the power changing lens  104  and the configuration of the first end  128  of the haptic  124  provide that the anterior portion of the capsular bag  62  remains spaced away from the power changing lens  104 . If the anterior portion of the capsular bag  62  were in contact with the first side  400 , the accommodating effect of the power changing lens  104  would be reduced. In various embodiments, the distance from the opening  136  to the first side  400  of the power changing lens  104  can be greater than or equal to about 0.6 mm and less than or equal to about 0.75 mm. In various embodiments, the distance from the opening  136  to the first side  400  of the power changing lens  104  can be about 0.01% of the axial height  148  of the haptic  124  to about 37% of the axial height  148  of the haptic  124 . Positioning the power changing lens  104  at a distance of about 0.01% of the axial height  148  of the haptic  124  to about 37% of the axial height  148  of the haptic  124 , from the opening  136  can advantageously reduce the risk of retinal detachment and PCO as a result of filling the capsular bag. The base member  102  alone and in combination with various second lenses disclosed herein can have a stable effective lens placement (ELP) and/or reduced post-implantation tilt or rotation issues as a result of filling or maintaining the volume of the natural capsular bag. Filling or maintaining the volume of the natural capsular bag can also result in stable refraction after implantation and/or reduced vitreo-retinal tension. Without ascribing to a particular theory, it is believed that by substantially maintaining the volume of the natural capsular bag the vitreous is prevented from shifting anteriorly. Positioning the power changing lens  104  at a distance of about 0.01% of the axial height  148  of the haptic  124  to about 37% of the axial height  148  of the haptic  124 , from the opening  136  can advantageously reduce inflammation after surgery. 
     The accommodating IOL device  100  includes a lens retention portion  164  configured to maintain the power changing lens  104  in an inset position within the cavity  160 . The lens retention portion  164  is spaced away from the opening  136  into the cavity  160  of the haptic  124 . The lens retention portion  164  can include a plurality of members, as discussed in greater detail below in connection with several figures. 
     Having discussed the accommodating IOL device  100  overall, further details of specific features will be discussed in greater depth. 
     C. Base Member Configurations 
     The general structure of the base member  102  is discussed above.  FIGS.  2 B,  3 A- 3 C and  5 - 7 A  illustrate various additional advantageous aspects of the base member  102 . 
     1. Base Lens and Haptic Interface 
       FIGS.  2 B and  9    show that the base lens  120  and the haptic  124  can be formed separately and then assembled to form base member  102 . In other embodiments the base member  102  is a single molded component with a monolithic structure. The haptic  124  can include the outer periphery  140  configured to contact the equatorial region  74  of the capsular bag  62  and the inner periphery  144  disposed inward of the outer periphery  140  as discussed above.  FIG.  9    shows that the haptic  124  also can include a lens interface portion, in one example a ring  292 , disposed radially inwardly of the inner periphery  144 . The ring  292  can be disposed posteriorly of equator contact segments  141  of the outer periphery  140 . The ring  292  can be disposed posteriorly of the second end  132  of the haptic  124 . The ring  292  can be disposed posteriorly of the second edge  156  of the haptic  124 . The position of the ring  292  relative to the equator contact segments  141  of the outer periphery  140  can be selected to place a posterior aspect of the base member  102  in direct contact with the anterior side of the posterior portion of the capsular bag  62  when the base member  102  is placed in the capsular bag  62 . The distance from the ring  292  or from the base lens  120  along the optical axis OA coupled therewith can be known and controlled and can be a factor in selection of the power changing lens  104  or of another non-accommodating lens, as discussed below. 
       FIG.  2 B  shows that the base lens  120  can be coupled with the haptic  124  at the ring  292  (or other lens interface portion). The base lens  120  can have a haptic interface surface  320 , which is one example of a haptic interface portion or a peripheral haptic interface portion, and the lens interface surface or portion  332  can have a ring  292 . In the illustrated embodiment the lens interface surface or portion  332  includes an annular area disposed about the inner periphery of the ring  292 . The lens interface surface or portion  332  can include a posterior surface of the ring  292 . In the illustrated embodiment the haptic interface surface  320  of the base lens  120  can include an annular skirt  321  disposed about the periphery of the base lens  120 . The haptic interface surface  320  can be a complete annulus in one embodiment. In other embodiments the haptic interface surface  320  can include a plurality of spaced apart members that are disposed about the circumference of the base lens  120 . The base lens  120  can be coupled with the haptic  124  at the surfaces or portions  320 ,  332  by any suitable means including using adhesives, welding or by interlocking connectors such as interference fit posts and recesses or features that can be snapped together, eliminating adhesives and stress concentrations or materials transformations associated with welding. 
     Stated differently, the base member  102  of an intraocular lens  100  can be assembled using the method described below, which includes coupling and securing the base member haptic  124  and the base lens  120 . The base member haptic  124  can include the lens interface portion  332  at the second end  132  that is opposite the first open end  128 . The lens interface portion  332  can include ring  292 . The base lens  120  can have a central optical portion  323  and a haptic interface portion  320 . The base lens  120  can have a periphery  325 , which can be circular or can be a cylindrical surface of the central optical portion  323  that faces away from the optical axis thereof, and that is sized to be inserted into the ring  292  of lens interface portion  332 . The haptic interface portion  320  can have an annular skirt  321 . 
     The haptic interface portion  320  of the base lens  102  can be coupled with the lens interface portion  332  of the base member haptic  124 . The cylindrical or circular periphery  325  of the base lens  120  can be inserted into the ring  292  of the lens interface portion  332  of the base member haptic  124  such that an anterior surface of the annular skirt  321  is coupled to a posterior surface  335  of the ring  292 . In some aspects, the lens interface portion  332  can include an opaque structure (e.g., a blue colored structure) and the base lens  120  can include an optically transmissive structure such that coupling the haptic interface portion  320  with the lens interface portion  332  includes transitioning from optically transmissive to optically opaque at an interface or boundary between the base lens  120  and the base member haptic  124 . 
     In some aspects, the haptic interface portion  320  includes an annular member, e.g., the skirt  321 , disposed radially outward of the central optical portion  323  and the lens interface portion  332  includes an annular structure, e.g., the ring  292 , disposed at the second end  132  of the base member haptic  124  such that coupling the haptic interface portion  320  to the lens interface portion  332  includes placing an anterior side of the annular member, e.g., the skirt  321 , against a posterior side  335  of the annular structure, e.g., the ring  292 . In some aspects, the haptic interface portion  320  includes a periphery  325  and the lens interface portion  332  includes an optical axis facing surface  333  facing an optical axis OA of the base lens  120  such that coupling the haptic interface portion  320  to the lens interface portion  332  includes advancing the periphery  325  of the central optical portion  323  along the optical facing surface  333  of the base member haptic  124 . 
     In some aspects, the haptic interface portion  320  includes a first transverse surface, e.g., an anterior-facing surface of the skirt  321 , disposed transverse to an optical axis OA of the base lens  120  and a first annular surface, e.g. the periphery  325 , disposed about an optical axis OA. The lens interface portion  332  can include a second transverse surface  335  (e.g., the posterior face of the ring  292 ) and a second annular surface, e.g., the optical facing surface  333  (e.g., the portion facing toward the center of the space in which the base lens  120  is mounted). Coupling the haptic interface portion  320  of the base lens  120  with the lens interface portion  332  of the base member haptic  124  can include disposing the first annular surface  325  at least partially within the second annular surface  333 , and disposing the first transverse surface  321  adjacent to the second transvers surface  335 . 
     The base lens  102  can be secured to the base member haptic  124  at the lens interface portion  332  and the haptic interface portion  320 . Securing the lens interface portion  332  and the haptic interface portion  320  can include applying an adhesive between an anterior surface of the annular skirt  321  and a posterior surface  335  of the ring  292 . Securing the lens interface portion  332  and the haptic interface portion  320  can include applying an adhesive between an inward surface  333  of the ring  292  and an outward surface  325  of the base lens  120 . The adhesive used to secure the lens interface portion  332  with the haptic interface portion  320  and the annular skirt  321  with the ring  292  can be the same material used to form the base lens  102 , the haptic  124  and/or other components of the intraocular lens  100 , which can include the materials described herein. The adhesive can be applied where the circular periphery  325  and the annular skirt  321  meet, which can result in the formation of a trough. The trough can include an area disposed around the location where the skirt  321  and the periphery  325  meet. The anterior surface of the skirt  321  can be inclined such that the free end thereof is at a higher elevation than the end joined to the periphery  325 . This construction helps contain the adhesive during assembly, such that the adhesive is maintained away from the optical surfaces of the base lens  120 . The base member haptic  124  can be made of a different material than the base lens  120 , but nonetheless, the adhesive used to secure the base member haptic  124  and the base lens  102  can be capable of joining or adhering the two different materials. 
     By forming the base lens  120  separate from the haptic  124 , the base member  102  can benefit from using materials that are adapted for the particular purpose. The base lens  120  can be formed from a material with: high optical quality, high compressibility, low coefficient of friction, beneficial tissue engagement properties for impeding posterior capsule opacification, or with any combination of these material properties. In one embodiment the base lens  120  is formed of silicone, but other materials that could be used include acrylic (e.g., hydrophobic and hydrophilic acrylics). Suitable silicone materials are biocompatible for the haptic  124 , including medical grade silicones, where preferably the cured material contains a low, negligible, or medically insignificant volume of compounds extractable by water, saline, or ocular fluids at about 37° C. Certain suitable silicone materials have a Young&#39;s modulus when cured of less than 100 psi (about 7×10 5  Pa), or even less than 50 psi (about 3.5×10 5  Pa), including 5-50 psi (about 3.5×10 4 -3.5×10 5  Pa), 10-40 psi (about 7×10 4 -3×10 5  Pa), and 10-35 psi (about 7×10 4 -205×10 5  Pa). Examples of suitable silicone materials include, but are not limited to, MED 4805, MED4810, MED4820, MED4830, MED5820, and MED5830 from NuSil®. For the optic examples of suitable silicone materials include, but not limited to, MED 6215, MED6210, MED6219, MED 6233 and MED6820. Suitable optic materials may also include a UV chromophore or UV absorbing group that may be blended with or bonded to a silicone component. In some such materials the UV chromophore or UV absorbing group is substantially non-extractible from the cured lens material by water, saline or ocular fluids at about 37° C. Embodiments of the base lens  120  comprising acrylic can be partially manufactured using molding methods and partially machined. The haptic  124  can be made of a material that is the same as or different from the material of the base lens  120 . The haptic  124  can be made of a material that is selected to be selectively stiff or incompressible. As discussed further below, the haptic  124  includes compression arms that preferably transfer a high percentage of force from a radially outward position to a radially inward position to produce a large amount of accommodation in the power changing lens  104  for a unit of ocular force. The material for the haptic  124  can also take into consideration a preference for circumferential compression, low friction coefficient, maintaining bulk properties over a large number of cycles, and other properties. One material suitable for the haptic  124  is silicone, including, but not limited to, the silicone materials listed above for the base lens, but other materials could be used. 
     In some variations discussed further below the base lens  120  is omitted. The base member  102  can include the ring  292  which can directly contact an annular area of the capsular bag disposed about the optical axis OA. The ring  292  can be extended further posteriorly to provide the same distance to the equator contact segments  141  or the distance can be varied and taken into account when the overall optical design of the power changing lens  104  is selected. 
     2. Lens Positioning Surfaces 
     The haptic  124  is configured to set the position of a lens disposed in the cavity  160 . The haptic  124  can be configured to set one more of the anterior-posterior location of one or both of the first side  400  and the second side  404  of the power changing lens  104 . The haptic  124  can be configured to set the orientation of one or both of the first side  400  and the second side  404  of the power changing lens  104  relative to the optical axis OA of the accommodating IOL device  100 . 
     The haptic  124  can have a surface or a plurality of surfaces that mate with the power changing lens  104  to set the position of the power changing lens  104  along the optical axis OA of the accommodating IOL device  100 .  FIG.  2 D  shows that the second side  404  of the power changing lens  104  is placed into the cavity  160  and a portion of the peripheral portion  408  on the second side  404  of the power changing lens  104  can come to rest on a plurality of support surfaces  170 . The support surfaces  170  can extend radially inward from the posterior end of compression arms  180 . Each support surface  170  can have an outer end  172  coupled with a posterior end of a corresponding compression arm  180  and an inner end  174  disposed radially inwardly of the outer end  172  (see  FIGS.  6  and  6 A ). 
     The circumferential extent of the support surfaces  170  can be the same at each of a plurality of spaced apart locations. The circumferential extent can extend over an arc of approximately 25 degrees, over an arc of approximately 20, over approximately an arc of 15 degrees, over an arc of approximately 10 degrees, or over an arc in a range of approximately 10-30 degrees, or over an arc in a range of approximately 15-20 degrees. The radial extent of the support surfaces  170  can be approximately 2-20% of the diameter of the second side  404  of the power changing lens  104 . In other embodiments the radial extent of the support surfaces  170  can be approximately 4-15%, 6-10%, or about 8% of the diameter of the second side  404  of the power changing lens  104 . 
     Preferably at least three of the support surfaces  170  are coplanar with each other. Preferably at least three of the support surfaces  170  are aligned in a common plane that is substantially transverse to, e.g., within about 2-5 degrees of perpendicular to, the optical axis OA of the accommodating IOL device  100 . In one embodiment three or more, e.g., all, of the support surfaces  170  are aligned in a plane perpendicular to the optical axis OA. In some cases, the support surfaces  170  are configured to contact the second side  404  of the power changing lens  104  and when in such contact to cause the optical axis of the power changing lens  104  to be less than 25 degrees offset form the optical axis of the base lens  120 . The support surfaces  170  can be configured to contact the second side  404  of the power changing lens  104  and when in such contact to cause the optical axis of the power changing lens  104  to be less than 15, less than 10, less than 5 or less than 3 degrees offset form the optical axis of the base lens  120 . In various embodiments, the edges of the haptic  124  and/or the base lens  120  can be rounded to reduce or mitigate the occurrence of dysphotopsia. For example, one or more edges in the optical path can be configured as rounded edges instead of sharp edges to reduce or mitigate dysphotopsia. As another example, the edges of the lens retention portion  164 , the edges of the equator contact segments  141 , the edges of one or more support surfaces  170  can be at least partially configured as rounded edges instead of sharp edges to reduce or mitigate dysphotopsia. Without any loss of generality, a plurality of the edges in a circular region of diameter 7 mm around a geometric center of the IOL device  100  can be configured as rounded edges instead of sharp edges to reduce or mitigate dysphotopsia. 
     Although the base member  102  is illustrated to have six support surfaces  170 , there could be fewer or more than six support surfaces  170 . In various embodiments there are four, three or two support surfaces  170  against which the power changing lens  104  is placed to position the power changing lens  104  in the base member  102 . 
     3. Haptic with Enhanced Circumferential Compressibility 
     The base member  102  and in particular the haptic  124  preferably has a high degree of compressibility to enhance insertion into the eye  50  and placement in the capsular bag  62 . One or both of the outer periphery  140  and the inner periphery  144  can be configured to enhance the circumferential compressibility of the haptic  124 . Although it is useful for the base member  102  to be rigid in a radially direction in select position, enabling the base member  102  to be circumferentially compressed allows the base member  102  to be inserted into the eye through a smaller incision. Also, circumferential flexibility allows small local shifting of zones of the haptic  124  during placement in the eye or during accommodation to enhance radial transmission of compression loads to the inner periphery  144  and the power changing lens  104  coupled therewith. 
       FIG.  3 B  shows that the outer periphery  140  can include an undulating periphery including a plurality of equator contact segments  141 . Each pair of adjacent equator contact segments  141  is separated by an external groove  224 . The external grooves  224  alternate between the equator contact segments  141 . Each equator contact segments  141  can be disposed between and bounded by an adjacent external groove  224 . Each adjacent pair of equator contact segments  141  can be separated by an intervening external groove  224 . The presence of the external groove  224  provides spaced apart contact regions with the equatorial region  74  of the capsular bag  62 . At each external groove  224  there is no contact with the equatorial region  74  of the capsular bag  62  at that location. The portion of the outer periphery  140  in direct compression transferring contact with the equatorial region  74  of the capsular bag  62  can be greater than or equal to about 50% of the circumference. For example, 50%-100% of the outer periphery  140  in direct compression transferring contact with the equatorial region  74  of the capsular bag  62 . As another example, the portion of the outer periphery  140  in direct compression transferring contact with the equatorial region  74  of the capsular bag  62  can be between about 55%-95%, between about 60%-90%, between about 75%-85%, or any value in any range/sub-range defined by these values. The portion of the outer periphery  140  in direct compression transferring contact with the equatorial region  74  of the capsular bag  62  can be greater than or equal to 180 degrees of the 360 degrees of the circumference. For example, portion of the outer periphery  140  in direct compression transferring contact with the equatorial region  74  of the capsular bag  62  can be in the range of 180-350 degrees of the 360 degrees of the circumference. As another example, the entire 360 degrees of the circumference of the outer periphery  140  can be in direct compression transferring contact with the equatorial region  74  of the capsular bag  62 . 
     The inner periphery  144  also has an undulating configuration in one embodiment. A plurality of compression members  180  are spaced apart from each other about the inner periphery  144 .  FIGS.  2 A and  3 A  show that the contact zones  184  of an array of compression arms  180  are configured to engaged corresponding spaced apart segments of the outer circumference of the peripheral portion  408  of the power changing lens  104 . The segments of the outer circumference of the peripheral portion  408  that are engaged by the contact zones  184 A are spaced apart by alternating zones of no contact. When the power changing lens  104  is disposed in the base member  102  a substantial minority of the circumference of the peripheral portion  408  of the power changing lens  104  is out of contact with the inner periphery  144  due to the undulating configuration of the inner periphery  144 . The compression members  180  apply compressive forces to the peripheral portion  408  at the spaced apart zone of contact as discussed further below. An internal groove  256  can be provided between adjacent pairs of contact zone  184 A of adjacent pairs of compression arms  180 . 
     In some embodiments, one or more of the external groove  224  is configure as an external hinge  220 . The external hinge  220  can be disposed in a portion of one or more of the compression arms  180 . The external hinge  220  provides for flexing at the outer periphery  140  of the haptic  124 . The flexing can cause adjacent portions of the compression arms  180  to move circumferentially toward or away from each other either in the process of compressing the base member  102  for implantation or when ocular forces are being applied to the base member  102 . The amount of flexibility of the external hinge  220  can be enhanced by extending the external groove  224  farther toward the inner periphery  144 . As a radially inward portion  226  of the groove is configured closer to the inner periphery  144  bending and folding of the outer periphery  140  can be enhanced at the same or lower loads. 
     The compressibility of the base member  102  can also be enhanced by enhancing the compressibility of an anterior portion  228  of the external hinge  220  in an anterior segment  162  of the haptic  124  while maintaining or even enhancing the stiffness of a posterior portion  232  of the external hinge  220  in a posterior segment  163  of the haptic  124 .  FIG.  7 A  shows that the posterior segment  163  corresponds to the location of the haptic  124  configured to receive and retain the power changing lens  104  (or another premium lens). The anterior segment  162  is disposed between the posterior segment  163  and the first edge  152  of the haptic  124 . As can be seen, the anterior portion  228  includes a span of the haptic  124  where circumferentially adjacent portion of the haptic  124  are not connected to each other whereas the posterior portion  232  provides a connection between adjacent segments in the form of the contact zones  184 A,  184 B,  184 C. This configuration allows the haptic  124  in the anterior segment  162  to be more compressible. Also, the external groove  224  can be seen to extend through the entire radial thickness of the haptic  124  from the outer periphery  140  to the inner periphery  144  in the anterior segment  162  of the haptic  124 . The external groove  224  can be seen to extend only as far as the portion of the compression arms  180  disposed radially outward of the contact zones  184 A,  184 B,  184 C. 
     The internal groove  256  can be configured as a portion of an internal hinge  252  in some embodiments. The internal groove  256  extends to a radially outward portion  258 . When configured as part of the internal hinge  252 , the internal groove  256  extends far enough to provide compressibility of the haptic  124  at the inner periphery  144  at a low force. In some embodiments to greatly increase flexibility of the haptic  124  for circumferential compression, the radially outward portion  258  of the internal groove  256  is radially outward of the radially inward portion  226  of the external groove  224 . Less circumferential compressibility is provided if the radially outward portion  258  of the internal groove  256  is radially inward of the radially inward portion  226  of the external groove  224 . 
     The hinges, grooves, and undulating configurations of various embodiments of the haptic  124  enhance circumferential compression without sacrificing transfer of compressive forces from the outer periphery  140  to the inner periphery  144  in the haptic  124  due to the configuration of a plurality of compression arms  180 . 
     4. Array of Arm Providing Power Changing Lens Compression 
     The accommodating IOL device  100  has a plurality of compression arms  180  configured to convey ocular forces from the equatorial region  74  of the capsular bag  62  to the peripheral portion  408  of the power changing lens  104 . The illustrated embodiment shows that the haptic  124  can have twelve compression arms  180  disposed in an array about the cavity  160 . The compression arms  180  can all have the same configuration or, as illustrated, can have more than one, e.g., two or three distinct configurations. The base member  102  can include a plurality of sets of compression arms  180 . The base member  102  can have a first configuration compression arm  180 A that includes a floating contact zone  184 A. The base member  102  can have a second configuration compression arm  180 B that has a retention contact zone  184 B. The base member  102  can have a third configuration compression arm  180 C that has a hinged contact zone  184 C. Each of these distinct configuration compression members  180  provides distinct function, compression performance, and advantages as discussed below including but not limited to stabilizing the refractive performance of the IOL device  100 , minimizing rotation of the IOL device  100  after implantation, improve ease of implantation of the IOL device  100  and/or improve ease of removing the implanted power changing lens  104  to replace with a different power changing lens at a future time. 
     a. Floating Compression Arms 
       FIGS.  3 A,  3 B,  5  and  5 A  show that the compression arm  180 A can be provided at some circumferential positions to contact a peripheral portion  408  of the power changing lens  104 . The compression arm  180 A is sometimes also referred to as a floating compression arm or a floating compression member because the force transferring portion disposed at the inner periphery  144  is not directly connected to another part of the haptic  124  or to the base lens  120 . The power changing lens  104  is omitted from FIG. to simplify the drawing, but the outer circumference of the peripheral portion  408  is shown in dash line. In one embodiment, the compression arm  180 A includes a floating contact zone  184 A. The floating contact zone  184 A is a radially inward portion of the compression arm  180 A that comprises a portion of the inner periphery  144  of the haptic  124 . The floating contact zone  184 A can have a circumferential surface that extends between a first circumferential end  192  and a second circumferential end  200 .  FIGS.  3 C and  5 A  also show that the floating contact zone  184 A has an anterior-posterior extent and thus the floating contact zone  184 A can be seen to have a curved but generally rectangular configuration. The anterior end of the floating contact zone  184 A is spaced from a first edge  152  of the haptic  124 . The contact between the peripheral portion  408  of the power changing lens  104  and the floating contact zone  184 A is on a circumferential radially outwardly facing area of the peripheral portion  408 . The contact between the peripheral portion  408  and the floating contact zone  184 A does not include contact on the first side  400  or the second side  404  of the power changing lens  104 . The contact can be over a fraction of the anterior-posterior length of the floating contact zone  184 A, e.g., over only 75% of that length, over 65% of that length, over 60% of that length, over 55% of that length, over 50% of that length, or over a length in the range of 40-80% of that length. 
     The circumferential extent of the floating contact zone  184 A can depend on how many contact zones are provided about the inner periphery  144 . In one embodiment there are six floating contact zone  184 A and each contact zone extends over an arc of approximately 25 degrees, over an arc of approximately 20 an arc of degrees, over approximately an arc of 15 degrees, over an arc of approximately 10 degrees, or over an arc in a range of approximately 10-30 degrees, or over an arc in a range of approximately 15-20 degrees. 
       FIGS.  3 A and  3 B  show that in some embodiments the floating contact zone  184 A are connected to adjacent compression arms  180  in a circumferential direction but are spaced apart from and the base lens  120 . The floating contact zones  184 A are connected to the adjacent compression arms  180  through relatively flexible connections, e.g., at internal grooves  256  or at internal hinge  252 . The floating contact zones  184 A are separated from other portions of the base member  102 , e.g., from an outer periphery of the base lens  120 , by a gap Ga (labeled in  FIG.  3 B ).  FIG.  3 B  shows that the floating contact zone  184 A and the gap Ga between floating contact zone  184 A and the base lens  120  can be provided in one-half the contact zones (e.g., six of twelve) about the inner periphery  144 . The gap Ga can be approximately constant along the circumferential direction of the floating contact zone  184 A. 
     Because the floating contact zones  184 A are in contact with the peripheral portion  408  only at the outwardly facing area of the outer circumference of the peripheral portion  408  there is no need to fit the first side  400  of the power changing lens  104  posterior to any aspect of the floating contact zone  184 A or the compression arm  180 A. This simplifies assembly while still enabling a compression force to be applied at the locations of the compression arm  180 A. Also, because the floating contact zones  184 A are in contact with only the outwardly facing area of the outer circumference there is no need to seat the second side  404  on an anteriorly facing portion of the compression arm  180 A in the peripheral portion  408  of the power changing lens  104 . This minimizes any rocking effect that can occur with variability in anterior-posterior position of a support surface configured to facilitate positioning of the power changing lens  104  along the optical axis OA of the accommodating IOL device  100 . 
     In addition to the floating contact zone  184 A, the compression arms  180 A each include a first radial force member  188  and a second radial force member  196 . Each of the force members  188 ,  196  is configured to transfer a compressive force from the outer periphery  140  of the haptic  124  to the inner periphery  144  of the haptic  124  during accommodation. The first radial force member  188  can be coupled at a first end with an end of a first equator contact segment  141  and at a second end with the first circumferential end  192  of the floating contact zone  184 A disposed radially inwardly of the first end of the equator contact segments  141 . The second radial force member  196  can be coupled with a first end to an equator contact segments  141  adjacent to the equator contact segments  141  to which the first radial force member  188  is connected. A second end of the second radial force member  196  can be coupled to the second circumferential end  200  of the floating contact zone  184 A. 
     As discussed above, the external groove  224  is provided in the outer periphery  140  of the base member  102 . The external groove  224  can be disposed between radially outer portions of the first radial force member  188  and the second radial force member  196 . The external groove  224  can extend sufficiently radially inwardly to provide an external hinge in the compression arm  180 A. By providing an external hinge in the compression arm  180 A, the response of the haptic  124  to circumferential compression of the eye can be maintained while providing enhanced circumferential compression. For example, as ocular forces create compression at the outer periphery  140  of the haptic  124  the facing edges of the equator contact segments  141  at the ends of the first radial force member  188  and the second radial force member  196  may be deflected toward each other (closing the gap around the section plane  5 A- 5 A in  FIG.  5   ). In this configuration the first radial force member  188  and the second radial force member  196  support each other enhancing transfer of radial forces inwardly to the power changing lens  104 . Additionally, the internal hinges  252  disposed between adjacent compressions arms  180  can advantageously enable a greater amount of compressive force from the eye to be focused in the radial force member  188 ,  196 . Without being bound by a particular theory, it is believed that this is because the internal hinges  252  bend at lower force and thus more of the total force applied to the haptic  124  is directed radially inwardly along and by the radial force member  188 ,  196  which together urge the contact zones  184  to the outer circumference of the peripheral portion  408  of the power changing lens  104 . 
     b. Compression Arm with Retention Portion 
       FIG.  3 B,  7  and  7 A  show details of a compression arm  180 B that can comprise one of a second set of compression arms. The compression arm  180 B is similar to the compression arm  180 A except as described differently herein. The compression arm  180 B includes a retention contact zone  184 B that includes a curved but generally rectangular contact zone for engaging an outer circumference of the peripheral portion  408 . The compression arm  180 B includes a lens retention portion  164  that projects from an anterior end of the retention contact zone  184 B. The retention contact zone  184 B, the lens retention portion  164  and the support surfaces  170  form a generally C-shaped space of the compression arm  180 B in which an arcuate segment of the peripheral portion  408  is received. The compression arm  180 B surrounds three sides of the power changing lens  104  at the peripheral portion  408  on the first side  400 , the, second side  404 , and on an outer circumference disposed between the first side  400  and the second side  404 . The support surfaces  170  supports a posterior side segment of the peripheral portion  408 , the retention contact zone  184 B supports a circumferential segment located on a radially outward side, and a posterior side of the lens retention portion  164  faces and supports an anterior segment of the peripheral portion  408 . 
     An anterior side of the lens retention portion  164  is recessed from the first edge  152  by an amount that allows the power changing lens  104  to be at a low profile position. For example, the power changing lens  104  can be recessed from the first edge  152  by an amount greater than or equal to about 0.6 mm and less than or equal to about 0.75 mm. For example, the power changing lens  104  can be recessed from the first edge  152  by a distance between about 0.01% of the distance from the first edge  152  to the second edge  156  of the haptic  124  and about 37% of the distance from the first edge  152  to the second edge  156  of the haptic  124 . The anterior side of the lens retention portion  164  is disposed adjacent to an opening  167  between the first radial force member  188  and the second radial force member  196 . The opening  167  extends from the first edge  152  down to a top edge of the retention contact zone  184 B. The opening  167  extends by more than 10% of the distance from the first edge  152  to the second edge  156  of the haptic  124 . The opening  167  extends by more than 20% of the distance from the first edge  152  to the second edge  156  of the haptic  124 . The opening  167  extends by more than 30% of the distance from the first edge  152  to the second edge  156  of the haptic  124 . The opening  167  extends from 10% to 40% of the distance from the first edge  152  to the second edge  156  of the haptic  124 . The opening  167  provides enhanced flexibility in the anterior segment  162  of the haptic  124 . 
     The compression arm  180 B advantageously provides three distinct functions. First the compression arm  180 B provides for radial compression of the power changing lens  104  by transferring compression of outer periphery  140  to the inner periphery  144 . The force can be transferred from the equator contact segments  141  to the first radial force member  188  and to the second radial force member  196 . The force can be transferred through the first radial force member  188  and second radial force member  196  in substantially equal amounts to the retention contact zone  184 B. Because the retention contact zone  184 B joins the radially inward ends of the radial force member  188 ,  196  any lack of uniformity can be balanced across the retention contact zone  184 B. A further function of the compression arm  180 B is axial position control. The support surface  170  at the compression arm  180 B provides axial position control to maintain the power changing lens  104  at a selected position. This function prevents the power changing lens  104  from being positioned farther posteriorly than planned and can help avoid poor distance vision in an unaccommodated state. The lens retention portion  164  provides a third function of the compression arm  180 B. The lens retention portion  164  prevents the power changing lens  104  from shifting axially along the optical axis OA of the accommodating IOL device  100  after the accommodating IOL device  100  is assembled in the eye  50 . Axial shifting could move the power changing lens  104  out of position in the cavity  160 . In an extreme case the power changing lens  104  could come out of the base member  102 , e.g., anterior of the capsular bag  62 . However, even movement partly or completely into the anterior segment  162  of the haptic  124  would degrade both distance vision and accommodation. Distance vision would be degraded because the unaccommodated position could be configured for the position in the posterior segment  163  of the haptic  124 . Accommodation would be degraded because the inner periphery of the haptic  124  in the anterior segment  162  has a larger inner diameter than the inner diameter defined by the retention contact zone  184 B and the opposing contact zone, e.g., the hinged contact zone  184 C. This larger inner diameter of the inner periphery  144  is larger than the outer diameter of the power changing lens  104 , e.g., of the peripheral portion  408  of the power changing lens  104 . Accordingly the inner periphery  144  may not even be in contact with the outer circumference of the power changing lens  104  when the accommodating IOL device  100  is in the unaccommodated state. 
       FIG.  7 A  shows that the distance in the anterior-posterior direction between the support surfaces  170  and the lens retention portion  164  is close to the thickness of the power changing lens  104 , between the first side  400  and the second side  404 . 
     c. Compression Arm with Device Support Surface 
       FIG.  3 B,  6  and  6 A  show details of the compression arm  180 C which can be one of another set of compression arms. The compression arm  180 C is similar to the compression arm  180 B but does not include the lens retention portion  164 . The power changing lens  104  is exposed on the first side  400  as shown in  FIG.  2 D . 
     The compression arm  180 C includes a hinged contact zone  184 C disposed at a radially inward end of the first radial force member  188  and the second radial force member  196 . The radial force members convey ocular forces from adjacent equator contact segments  141  to the hinged contact zone  184 C. The hinged contact zone  184 C includes a curved surface that extends between the radial force members  188 ,  196 . The anterior edge of the hinged contact zone  184 C is open or exposed radially inwardly and anteriorly thereof. The posterior edge of the hinged contact zone  184 C is coupled with the outer end  172  of the support surface  170 . The compression arm  180 C provides engagement with the power changing lens  104  on two surfaces. The second side  404  in the peripheral portion  408  of the power changing lens  104  faces and is supported by the support surface  170 . The support surface  170  of the compression arm  180 C provides axial positioning of the power changing lens  104  along the optical axis OA. A second surface of engagement is provided at the hinged contact zone  184 C, which contacts the outer circumference of the peripheral portion  408  of the power changing lens  104 . 
     An advantage of the compression arm  180 C is that axial positioning can be provided to the power changing lens  104  and compression force can be applied to the outer circumference at the peripheral portion  408 . The first radial force member  188  and the second radial force member  196  are able to move circumferentially relative to each other due to the external groove  224  which can be configured to provide an external hinge  220 . A further advantage is that these functions can be provided with having to position the first side  400  posterior to a retention portion or tab when assembling the power changing lens  104  to the base member  102  in the eye  50 . 
     5. Radial Hinge Coupling of Arms and Base Lens 
     As discussed further below, the base member  102  is configured to fill the capsular bag  62  in part to restore the capsular bag  62  to a volume similar to the volume of the crystalline lens  54  prior to the capsulotomy. There are several benefits to restoring the volume of the capsular bag  62 , as discussed above, including reducing, minimizing or preventing fibrosis between anterior and posterior portions of the capsular bag  62 , establishing a predictable and stable position for the power changing lens  104  or other secondary ocular device to be placed in the base member  102 , and/or engaging the outer periphery  140  of the haptic  124  with the equatorial region  74  of the capsular bag  62 . The base member  102  can be configured to consistently position the equator contact segments  141  at the equatorial region  74 . 
     In one embodiment one or a plurality of radial hinges  280  are provided disposed between the ring  292  and the inner periphery  144  of the haptic  124 . The radial hinges  280  extend along opposing segments of three diameters of the radial hinge  280 , e.g., at the diameter aligned with section plane  3 C- 3 C in  FIG.  3 B  and at two diameters spaced +60 degrees and −60 degrees from the section plane  3 C- 3 C. The radial hinges  280  are sometimes referred to as diametrical hinges herein.  FIGS.  3 C and  6 A  show that the radial hinge  280  can extend from a first portion  282  coupled with and assembly including the base lens  120  to a second portion  284  coupled with a portion of the haptic  124 . The first portion  282  can be coupled with the ring  292 . The second portion  284  can be coupled with the support surface  170  of one of the compression arms  180 .  FIG.  3 C  shows that the first portion  282  of one of the radial hinges  280  can be coupled along an arc of the ring  292  and the second portion  284  can be coupled with the compression arm  180 B, e.g., along an arc of the outer end  172  of the support surface  170  coupled with the hinged contact zone  184 B.  FIG.  3 C  also shows that the first portion  282  of one of the radial hinges  280  can be coupled along an arc of the ring  292  and the second portion  284  can be coupled with the compression arm  180 C, e.g., along an arc of the outer end  172  of the support surface  170  coupled with the hinged contact zone  184 C. 
     The radial hinges  280  can be positioned in an array at a plurality of positions about the base member  102 . The radial hinges  280  connect the compression arms  180  to the base lens  120 . The connection can be directly to the base lens  120  or can be indirectly, e.g., at the ring  292  as discussed above.  FIGS.  3 A- 3 C  show that the radial hinge  280  can connect each of the compression arm  180 B and the compression arm  180 C to the ring  292  and, indirectly, to the base lens  120 . The radial hinges  280  are disposed at alternating arms of the plurality of compression arms  180 . In the base member  102  there are six radial hinges  280 . In the base member  102  three of the radial hinges  280  are disposed at the same angular position as lens retention portion  164  and two of the radial hinge  280  are spaced equally apart from two adjacent lens retention portion  164 . The two adjacent lens retention portion  164  can be 120 degrees apart. Two radial hinges  280  can be 60 degrees apart from each of two adjacent lens retention portion  164 . 
     The radial hinge  280  provide at least two functions to the base member  102 . First, the radial hinge  280  enable a ring shaped body of the haptic  124  that is disposed between the first edge  152  and the second edge  156  to be compressed to the assembly including the ring  292  and the base lens  120  (if present). The compression of these components together enables the base member  102  to be inserted into the eye  50  in a more compact configuration. The radial hinges  280  also provide freer movement of the inner periphery  144  toward the optical axis OA of the accommodating IOL device  100  upon compression of the capsular bag  62 . The posterior surface  123  of the base lens  120  can be placed against the inside anterior-facing surface of the posterior segment of the capsular bag  62 . The outer periphery  140  can be placed in the equatorial region  74  of the capsular bag  62 . Posterior movement of the posterior surface  123  upon compression of the equatorial region  74  is reduced or prevented by the vitreous fluid posterior to the capsular bag  62 . The radial hinge  280  then focus movement of the posterior segment  163  of the haptic  124  radially inward toward the optical axis OA upon compression of the equatorial region  74 . The radial hinges  280  are configured such that the second portion  284  tilts radially inwardly toward the optical axis OA upon compression of the inner periphery  144  by ocular forces of the equatorial region  74 . 
     Although six radial hinge  280  are shown, the base member  102  could be configured with fewer or more hinges. Also, although the configurations of the radial hinges  280  can have substantially the same configuration, the radial hinges  280  coupled with the compression arm  180 B can have more flexibility in view of the enhanced stiffness imparted by the lens retention portion  164 . 
     6. Lens Retention Portions 
     As discussed above a critical function of the accommodating IOL device  100  is to retain the power changing lens  104  within the cavity  160  of the base member  102 . In the accommodating IOL device  100  the power changing lens  104  is delivered separately from the base member  102 , e.g., in the same procedure and through the same incision. The base member  102  is configured to provide enhanced compression of the power changing lens  104  by disposing the power changing lens  104  in the posterior segment  163 . This is further desired to retain the base member  102  in the posterior segment  163  of the cavity  160 . 
     In the illustrated embodiment the lens retention portion  164  is provided within the cavity  160 . The lens retention portion  164  is disposed at the boundary of the posterior segment  163  and the anterior segment  162 . The lens retention portion  164  can include a plurality of, e.g., three, tabs that extend toward the center of the cavity  160 . The tabs have a bottom surface configured to be in contact with the power changing lens when implanted and an upper surface facing the opening  136  of the haptic  124 . The tabs can be disposed such that an axial distance from the anterior most portion of the haptic  124  to the upper surface of the tab is greater than or equal to about 0.6 mm. For example, the axial distance from the anterior most portion of the haptic  124  to the upper surface of the tab can be greater than or equal to about 0.6 mm and less than or equal to about 0.75 mm, greater than or equal to about 0.7 mm and less than or equal to about 0.9 mm, greater than or equal to about 0.8 mm and less than or equal to about 1.0 mm, greater than or equal to about 0.9 mm and less than or equal to about 1.1 mm, greater than or equal to about 1.0 mm and less than or equal to about 1.25 mm, or any value in any range/sub-range defined by any of these values. In various embodiments, the tabs can be positioned at a distance from the edge of the haptic  124 , of about 0.01% of the height  148  of the haptic  124  to about 37% of the height  148  of the haptic  124 . The tabs and the support surfaces  170  define spaces for surrounding and holding spaced apart arcs of the peripheral portion  408  of the base lens  120 . More particularly, the lens retention portion  164  can be configured as a projection  344  having an outer portion  348 , and inner portion  352  and an elongate portion  354  disposed therebetween. The inner portion  352  can be coupled with, an extension of or disposed adjacent to an anterior portion of the hinged contact zone  184 C of the compression arm  180 C. The elongate portion  354  can extend radially, or along a diameter of the base member  102 . The elongate portion  354  can include a planar posterior surface that faces and contacts the first side  400  of the power changing lens  104 .  FIGS.  2 A and  2 D  show that the outer portion  348  extends well inward of the outer circumference of the power changing lens  104 . The outer portion  348  can extend to a position radially between the outer circumference of the power changing lens  104  and the outer periphery of a flexible membrane  402  of the power changing lens  104 . The outer portion  348  can be located radially outward of an outer circumference of the flexible membrane. 
     As discussed further below, the peripheral portion  408  of the power changing lens  104  can include an annular segment that is outward of the optical surfaces thereof. The annular segment can extend between an outer circumference of the peripheral portion  408  and a closed cavity  412  of the power changing lens  104 . The annular portion can be configured as a solid annulus between the closed cavity  412  and the outer circumference of the peripheral portion  408 . The outer portion  348  of the projection  344  can be disposed across the annulus, e.g., at least one-half of the distance from the outer circumference of the peripheral portion  408  to the outer circumference of the membrane  402 . The width of the elongate portion  354  between the projection outer portion  348  and the inner portion  352  can extend over an arc of approximately 30 degrees, over an arc of approximately 25 degrees, over approximately an arc of 20 degrees, over an arc of approximately 15 degrees, or over an arc in a range of approximately 15-40 degrees, or over an arc in a range of approximately 20-30 degrees. 
     The projection  344  preferably is flexible at the outer portion  348  such that the outer circumference of the peripheral portion  408  can be extended under the posterior side of the elongate portion  354 . However, the projection  344  is rigid at the inner portion  352  such that compressive forces of the compression arms  180  do not significantly deflect the inner portion  352 . 
       FIG.  8    shows another embodiment of the base member  102 A that is similar to the base member  102  in which the lens retention portion  164  is altered. The base member  102 A can include any of the structures described above in connection with the base member  102 . The base member  102  includes a retention portion  164 A configured to enhance visibility of the proper position of the power changing lens  104  within the base member  102 . As seen in  FIG.  8 C , the retention portion  164 A can include an end portion that is rounded or curved, which can differ from the more straight end portion of the retention portion  164 , as illustrated in  FIG.  2 A . The lens retention portion  164 A includes an elongate portion  354 A with a visible guide structure  370 . The visible guide structure  370  can include one or a plurality of, e.g., two ridges  372  that are visible when the base member  102 A is placed in the eye  50 . The ridge  372  includes an outer end  374  and an inner end  376 . The outer end  374  can be disposed adjacent to a radially inner end of the external groove  224  in the outer periphery  140 . The inner end  376  can be disposed at or adjacent to the radially inner end of the elongate portion  354 .  FIG.  8 A  shows a cross-section at section plane  8 A- 8 A in the detail view of  FIG.  8   . 
     Any one of the guide structure  370  can be visible to the clinician when the base member  102  has been placed in the eye. If the base lens  120  is axisymmetric, e.g., aspheric or monofocal lacking any cylinder power, the surgeon can simply confirm that all three (or more) of the guide structures  370  on the three (or more) projection  344 A are visible as depicted in  FIG.  8 C . If the base lens  120  has cylinder power the surgeon can confirm that the projection  344 A is properly oriented. For example, one of the guide structure  370  can be configured as arrows pointing superiorly when the cylinder power is properly aligned in the eye. If the guide structure  370  of any of the projection  344 A is not clearly visible, for example, as shown in  FIG.  8 B , the surgeon can conclude that the power changing lens  104  is on top of (anterior of) the projection  344 A and would be advised to manipulate the projection  344 A to place the peripheral portion  408  of the power changing lens  104  posteriorly thereto. The guide structures  372  may be seen to extend radially inward of the outer circumference of the peripheral portion  408  if the projections  344 A are posterior to the power changing lens  104 . In other techniques, the visible length of the ridges  372  can be measured and if one or more is seen to be shorter in the radial direction than the others, the projection  344 A can be concluded to be positioned under the power changing lens  104  and an appropriate adjustment can be made. For example, an instrument can be placed under the projection  344 A to lift the projection over (anterior to) the power changing lens  104 . 
     D. Power Changing and Fixed Power Lenses 
       FIGS.  2 A- 2 D and  4 A- 4 D  depict various examples of the power changing lens  104  in detail and  FIGS.  4 E- 4 F  show examples of premium IOLs and other IOLs with fixed optical designs or powers all of which can be used in the base member  102 . The power changing lens  104  includes a flexible membrane  402 , an optic  406  and an outer circumference  409 , which may be referred to as a circumferential peripheral edge. The outer circumference  409  couples the flexible membrane  402  to the optic  406 . A membrane coupler  410  is disposed from the outer circumference  409  to couple the flexible membrane  402  with the outer circumference  409 . Similarly, an optic coupler  411  is disposed from outer circumference  409  to couple the optic coupler  411  with the outer circumference  409 . Preferably, the optic coupler  411  is angled toward the flexible membrane  402  such that it positions the optic  406  toward the flexible membrane  402 . 
     The structure of the power changing lens  104  is simplified by not requiring any traditional elongate thin haptic structures. Rather the peripheral portion  408  is formed as an annulus. The axisymmetric structure enables the power changing lens  104  to be positioned in any rotational position within the cavity  160  in embodiments without cylinder power on the optic  406 . Any rotational position of the power changing lens  104  in the base member  102  will provide uniform compression and such compression will provide uniform power change primarily by changing the shape of the flexible membrane  402 . For example, ocular forces exerted by the eye can be uniformly compress the power changing lens such that an average change in optical power along any of transverse axes M 1 , M 2 , M 3  and M 4  depicted in  FIG.  2 A- 1    is within ±25% of a nominal optical power. The power changing lens  104  provides a fluid filled lens with one membrane. The optic  406  is a moving optic. The power changing lens  104  changes power through diametrical compression of the peripheral portion  408  in response to ocular forces. Such forces deflect the flexible membrane  402  as indicated by the dashed line anterior of (above) the solid line position of the flexible membrane  402  in  FIG.  4 B . The optic  406  also moves in response to compression of the peripheral portion  408  as indicated by the dash line anterior of (above) the optic  406  in  FIG.  4 B . Without subscribing to any particular theory, the uniformity of the power change can be measured using a bench-top measurement system. The bench-top measurement system can comprise a cylindrical device that can hold the IOL device  100  including the base member  102  and the power changing lens  104  in a compressed state similar to the accommodated state in the eye of the patient. The amount of compressive force applied by the cylindrical device can be sufficient to achieve a power change equivalent to an optical power of 4.0 Diopter in the IOL plane. The power change of the IOL device  100  can be considered to be uniform if the average optical power measured along any of the transverse axes M 1 , M 2 , M 3  and M 4  is between 3.0 Diopter and 5.0 Diopter in the IOL plane. 
     The optic  406  is not a major or main driving force in the change in shape of the flexible membrane  402 . Rather, the optic  406  follows the movement of the flexible membrane  402  in response to shifting of the fluid in the closed cavity  412 . The optic  406  can be considered to be floating on the fluid in the closed cavity  412  and thus anterior movement of the fluid in response to ocular forces causing compression of the peripheral portion  408  as indicated by arrows A allows the optic  406  to shift anteriorly. Posterior movement of the fluid in response to relaxation of the peripheral portion  408  as indicated by removal of ocular forces in a direction opposite arrows A allows the optic  406  to shift posteriorly. The shifting of the fluid and the optic  406  minimizes distortion of the power changing lens  104  and thus minimizes any dysphotopsia and any other optical interference during power change. The arrows shown within the cross-section in  FIG.  4 B  are intended to show the compression force F divided into components in the power changing lens  104 . The vast majority of the force F is driven into the flexible membrane  402  due to the membrane being in the plane of the equator contact segments  141  in the posterior segment  163  of the haptic  124 . This is due to the deep set position of the power changing lens  104  in the base member  102 . Some force may be transferred into the optic coupler  411 . However, a response to this force can be articulating the coupler rather than directly moving the optic  406  forwardly. Thus even the force distribution within the power changing lens  104  attenuates anterior movement driven in response to the compression force F. 
     The configuration of the power changing lens  104  to enable the optic  406  to follow anterior shape change of the flexible membrane  402  enables the posterior surface of the optic  406  to be placed adjacent to the anterior surface  122  of the base lens  120 . The distance between these structures can be 0.5 mm or less, can be 0.4 mm or less, can be 0.3 mm or less, can be about 0.2 mm, or can be 0.2 mm or less. The close positioning of these structures enables the deep inset position of the power changing lens  104  in the base member  102 . 
     In some embodiment the performance of the power changing lens  104  is dependent on placing the power changing lens  104  in the eye such that the flexible membrane  402  is anterior of the optic  406 . Also, the manner in which the power changing lens  104  is compressed for insertion into the eye can be critical to successful delivery into the eye. Certain variants aid quickly confirming the orientation of the power changing lens  104 . 
       FIGS.  4 A- 4 B  show an optional additional visible color structure  409  that can provide confirmation of the orientation of the power changing lens  104 , e.g., to positively identify the location of the flexible membrane  402  and the optic  406 . The power changing lens  104  can have a visible color structure  409  disposed in the peripheral portion  408 . The visible color structure  409  has an at least partially opaque dye or pigment. The opaque dye or pigment can be any color, which can include red, orange, yellow, green, blue, indigo, violet, and/or any other suitable color or combination of colors. The visible color structure  409  can be a variety of cross-sectional sizes and shapes, which can be continuous or varied. For example, the visible color structure  409  can be a complete annulus that is visible from a peripheral, an anterior and/or a posterior side. The visible color structure  409  can include one or a plurality of arcs or arc segments visible from a peripheral, an anterior and/or a posterior side. The visible color structure  409  is disposed between an anterior portion and posterior portion of the peripheral portion  408  such that the at least partially opaque dye or pigment of the visible color structure  409  is contained in the power changing lens  104  and positioned radially outward of an optical axis A and in some cases outward of a closed cavity  412  of the lens  104 . The visible color structure  409  is disposed between a first side  400  (anterior side) and a second side  404  (posterior side) of the power changing lens  104 . The visible color structure  409  is disposed closer to the posterior portion than to the anterior portion of the peripheral portion  408  in one example. This positioning enables convenient visual verification of the orientation of the power changing lens  104 . The visible color structure  409  is positioned closer to a plane tangential to the posterior surface of the optic  406  than to a plane tangential to an anterior surface of the flexible membrane  402 . Accordingly, when viewed from the side, the side of the power changing lens  104  that is closest to the visible color structure  409  is the side of the optic  406 , e.g., the second side  404 , while the side that is farthest from the visible color structure  409  is the side of the flexible membrane  402 , e.g., the first side  400 . 
     The visible color structure  409  can provide a visual verification that the power changing lens  104  is loaded correctly into a injector  480 , as seen in  FIG.  11   . For example, the visible color structure  409  can visually indicate that the power changing lens  104  is loaded into the injector  480  with the flexible membrane  402  folded onto itself such that the flexible membrane  402  is protected from damage and that the power changing lens  104  will exit the injector  480  with the first side  400 , e.g., the flexible membrane  402  facing up. Alternatively, the visible color structure  409  can be disposed closer to the anterior portion than to the posterior portion of the peripheral portion  408 . 
     In some aspects, the visible color structure  409  can be used to visually verify that the power changing lens  104  is secured within the base member  102  by the lens retention portions  164 . For example, the visible color structure  409  can be a continuous annular shape that is visually disrupted, when viewed from above, by the lens retention portions  164  (if the lens retention portions  164  are opaque or have a solid color, as described elsewhere herein) when the power changing lens  104  is secured within the base member  102  by the lens retention portions  164 . Accordingly, the power changing lens  104  is secured by a given lens retention portion  164  when the visible color structure  409  is disrupted, when viewed from above, at the position of the given lens retention portion  164 . Relatedly, the power changing lens  104  is not secured by a given lens retention portion  164  when the visible color structure  409  is not disrupted, when viewed from above, at the position of the given lens retention portion  164 . 
     In some aspects, the visible color structure  409  can be combined with an adhesive that joins the anterior portion and posterior portion of the peripheral portion  408 . The adhesive can be the same material as the power changing lens  104  or another suitable material. In some aspects, the visible color structure  409  is rotationally symmetrically disposed about the optical axis A. The visible color structure  409  can be an arcuate band surrounding the optical axis A. In some aspects, the visible color structure  409  reduces observable glare transmitted through the peripheral portion  408 .  FIGS.  4 C- 4 D  show examples of a power changing lens  104 A that is similar to the power changing lens  104  except as described differently below. The power changing lens  104 A has a rotational position feature  413  that is configured to provide simultaneous confirmation of orientation about at least two axes. The rotational position feature  413  can be disposed on or in a peripheral portion of the power changing lens  104 A. In one variation, the rotational feature  413  is a visible mark that is oriented in a first direction upon orienting the first side  400  (anterior side) to face an observer and in a second direction, opposite the first direction, upon orienting the first side  400  (anterior side) to face away from an observer. In some aspects, the rotational position feature  413  includes a first mark disposed on a first side of the first side  400  (anterior side) and a second mark disposed on a second side of the first side  400  (anterior side). 
     In some aspects, as illustrated in  FIGS.  4 C- 4 D , the rotational position feature  413  includes an array of dots that confirm orientation about an axis that is oriented perpendicular to the optical axis A. The array of dots can be configured to confirm orientation. For example, the array of dots can include two sets of three dots on opposite sides of a periphery of a surface of the lens  104 A, e.g., with the optical axis A disposed between the two arrays of dots. In  FIG.  4 C , the rotational position feature  413 , the arrays of dots, point in a clockwise direction about the optical axis A, which indicates that the power changing lens  104 A is positioned with the first side  400  (anterior side) and flexible membrane  402  facing toward an observer. In  FIG.  4 D , the rotational position feature  413 , the array of dots, point in a counterclockwise direction about the optical axis A, which indicates that the power changing lens  104 A is positioned with the first side  400  (anterior side) and flexible membrane  402  facing away from an observer and the second side  404  (posterior side) and optic  406  facing towards the observer. In other embodiments the array of dots can be configured to point counter-clockwise about the optical axis A to indicate that the power changing lens  104 A is positioned with the first side  400  (anterior side) and flexible membrane  402  facing toward an observer and the second side  404  (posterior side) and optic  406  facing away from the observer. 
     The rotational position feature  413 , e.g., an array of dots, can be formed on an anterior surface, a posterior surface, or an anterior surface and a posterior surface of a peripheral portion of the flexible membrane  402 . The rotational position feature  413 , e.g., an array of dots, can be formed on a membrane coupler of the power changing lens  104 A. The rotational position feature  413 , e.g., an array of dots, can be formed on an anterior surface of the peripheral portion  408  of the power changing lens  104 A. The rotational position feature  413 , e.g., an array of dots, can be formed on a posterior surface of the peripheral portion  408  of the power changing lens  104 A. The rotational position feature  413 , e.g., an array of dots, can be formed on an optic coupler  411  of the peripheral portion  408  of the power changing lens  104 A. The rotational position feature  413 , e.g., an array of dots, can be formed on an anterior surface, a posterior surface, or an anterior surface and a posterior surface of a peripheral portion of the optic  406  of the power changing lens  104 A. 
     In some aspects, as illustrated in  FIGS.  4 C- 4 D , the rotational position feature  413  includes an array of dots that confirm orientation about the optical axis A. The rotational position feature  413  can be aligned with a transverse axis relative to the optical axis A. For example, the rotational position feature  413  can be aligned with any of the transverse axes M 1 , M 2 , M 3  and M 4  illustrated in  FIG.  2 A- 1    by rotating the power changing lens  104 A until the rotational position feature  413 , the two sets of arrays of dots, are positioned along the desired axis. The rotational position features  413  can be applied to any lens with rotationally differentiated optics. The rotational position features  413  can be especially advantageous when positioning a toric lens to correct astigmatism. 
     Further details of the power changing lens  104  can be found in US20160030161A1, which is incorporated by reference herein in its entirety for all purposes. 
     E. Intra-Ocular Assembly Methods and Systems 
     As discussed above, the accommodating IOL device  100  is configured to be assembled in the eye. This configuration enables the accommodating IOL device  100  to be inserted through smaller incisions than would be possible if the accommodating IOL device  100  were fully pre-assembled. 
     1. Intra-Ocular Assembly Methods 
       FIG.  10 A  shows the eye  50  prior to a surgical procedure to implant the accommodating IOL device  100 . Although the crystalline lens  54  is shown with uniform optical properties, the eye  50  may be suffering from cataract clouding the crystalline lens  54 . The eye  50  may also be suffering from presbyopia which can result when the crystalline lens  54  has become rigid and lacking flexibility to allow the ciliary muscle  70  to deform the lens via the zonules  66  to change the power of the lens. The accommodating IOL device  100  can treat both of these conditions. 
       FIG.  10 B  shows the eye  50  following a capsuolotomy. The capsulotomy can start by forming an opening  58  in the front of the crystalline lens  54 . The opening  58  is sometimes referred to as a capsulorhexis and can be formed by a scalpel, by a femtosecond laser system or by other techniques. Thereafter the internal volume of the crystalline lens  54  is removed, leaving a sac-like structure referred to herein as the capsular bag  62  The contents can be removed by phacoemulsification or by femto-second laser or by other techniques. 
       FIG.  10 C  shows the base member  102  being inserted into the capsular bag  62 . The base member  102  is highly compressed by virtue of the configuration of the hinges and undulating structure of the haptic  124  at and between the outer periphery  140 . The base member  102  is highly compressed by virtue of the configuration of the hinges between the inner periphery  144  and the ring  292 . The enhanced flexibility for compression enables the base member  102  to be inserted through an incision I 1  less than or equal to about 3.0 mm. For example, a size of the incision I 1  through which the base member  102  can be inserted can be less than or equal to about 2.7 mm, less than or equal to about 2.5 mm, less than or equal to about 2.2 mm and greater than about 1.8 mm. The base member  102  is compressed by folding about a transverse axis TA, e.g., an axis that is perpendicular to the optical axis OA (see  FIG.  3 C ). The base member  102  can be folded such that opposing portions of the haptic  124  at the first edge  152  of the haptic  124  are brought together. The opposing portions of the haptic  124  may be touching each other, as shown in  FIG.  10 C . In one embodiment, the base member  102  is rolled such that a posterior aspect of the haptic  124  is tucked between an anterior aspect of the haptic  124  and a central area of the fold. After the base member  102  has been folded and/or rolled, it can be coupled with or disposed in an injector  480 , shown in part and discussed below in connection with  FIG.  11   . The injector  480  includes an injector barrel  484  and a plunger  492 . A plunging force aligned with the longitudinal axis  500  can push the rolled and/or folded base member  102  into the capsular bag  62 . 
       FIG.  10 D  shows that the rolled and/or folded base member  102  is advanced out of an injector  480  into the capsular bag  62  with the cavity  160  facing anteriorly. This position is not required but advantageously enables the base member  102  to unfold with the cavity  160  facing anteriorly such that the power changing lens  104  can be inserted without having to inverted the base member  102  to cause the cavity  160  to face anteriorly. The base lens  120  is unfolded such that the equator contact segments  141  are disposed in the equatorial region  74  of the capsular bag  62 . Once so positioned the orientation of the base member  102  can be confirmed if the base lens  120  has cylinder power or is otherwise configured to provide optimal optics in one or over a small range of angular positions. As discussed above, the lens retention portion  164 A can be configured to visual cue the surgeon as to the orientation of a meridian, diameter or other region with a preferred rotational orientation. Other orientation confirming visual cues or indicia can be used, for example an arrow pointing toward the lens retention portion  164  to be aligned to or disposed opposite of (or at a different position) relative to the incision I 1 . 
       FIG.  10 E  shows the base member  102  fully expanded, e.g. unfolded and/or unrolled. The cavity  160  is facing anteriorly such that another device can be positioned therein. If the rotational orientation of the base member  102  is not as intended, e.g., a cylinder power of the base lens  120  is not in the planned position the method can include rotationally orienting the base member  102  as indicated by the arrow B. The rotation according to the arrow B can be in a shortest arc to provide the proper orientation. 
       FIG.  10 F  shows that after the base member  102  has been unfolded and/or unrolled in the capsular bag  62  the power changing lens  104  can be delivered. Preferably the power changing lens  104  is delivered through the same incision, although in one embodiment the power changing lens  104  is delivered through a second incision I 2  disposed 180 degrees away from the incision through which the base member  102  is placed. The power changing lens  104  is shown folded or rolled in an opposite orientation to that of the base member  102 .  FIG.  10 E- 1    shows that the second side  404  is folded into an interior region of the fold. The power changing lens  104  when folded or rolled is then oriented such that the posterior surfaced (the second side  404 ) is oriented posteriorly (i.e., rotated 90 degrees from the orientation shown in  FIG.  10 E- 1   ). When placed in the cavity  160  the power changing lens  104  can unfold with the outer circumference  409  of the peripheral portion  408  extending along the posterior segment  163  of the haptic  124  into position under the lens retention portions  164  and on top of the support surfaces  170 . 
       FIGS.  10 E- 1  and  10 E- 2    show various techniques for inserting the power changing lens  104  in simplified schematics of the base member  102  and the power changing lens  104 .  FIG.  10 E- 1    shows the power changing lens  104  folded or rolled as described in connection with  FIG.  10 F . A concave side of a fold or roll would be oriented facing anteriorly (90 degrees into the page). In this configuration the first side  400  of the power changing lens  104  (e.g., the flexible membrane  402 ) is on the outside of the fold or roll and the optic  406  is on the inside of the fold or roll. The orientation of the power changing lens  104  can be visually verified with the visible color structure  409 , which is described in more detail in reference to  FIGS.  4 A and  4 B , to correctly load the power changing lens  104  into the injector  480 . As illustrated in  FIG.  10 E- 1   , the visible color structure  409  is positioned between the first side  400  and the second side  404  and closer to the second side  404  than the first side  400 . The visible color structure  409  visually indicates that the second side  404  and the optic  406  are on the inside of the fold or roll while the first side  400  and the flexible membrane  402  are on the outside of the fold or roll when loading the power changing lens  104  into the injector  480 . The base member  102  is oriented in the capsular bag  62  (by motion along the arrows B if needed) such that one of the projection  344  is aligned with an incision I 1 . Thereafter the rolled or folded power changing lens  104  is inserted directly over the projection  344  that is aligned with the incision I 1 . Once the power changing lens  104  crosses over the projection  344  that is aligned with the incision I 1  the power changing lens  104  is partly advanced out of the injector  480  (as in  FIG.  10 G ) such that a leading edge of the power changing lens  104  upon insertion can be unfolded and/or unrolled and advanced under the other two projections  344  prior to full release of the power changing lens  104  in the base member  102 . 
       FIG.  10 E- 2    shows a different approach. The power changing lens  104  is folded or rolled and advance over into the eye in an incision I 2  that is opposite to one of the projection  344 . The incision I 2  is disposed between, e.g., equally spaced from the other two projections  344  of the lens retention portion  164 . The relative position of the projections  344  to the incision I 2  can be achieved by movement of the base member  102  according to the arrow B. The incision I 2  is shown opposite to the position of the incision I 1  but in general the incisions I 1  and I 2  can be in the same location or any suitable position. The position can be driven by other factors such as ease of access or corneal contributions to refraction or to higher order aberrations. In the approach of  FIG.  10 E- 2    the power changing lens  104  can be folded or rolled in the opposite direction such that the first side  400  (e.g., the flexible membrane  402 ) is on the concave or inside of the fold or roll. The second side  404  (e.g., the optic  406 ) is on the convex or outside of the fold or roll. As illustrated in  FIG.  10 E- 2   , the visible color structure  409  is positioned between the first side  400  and the second side  404  and closer to the second side  404  than the first side  400 . Accordingly, the visible color structure  409  visually indicates that the first side  400  and the flexible membrane  402  are on the inside of the fold or roll while the second side  404  and the optic  406  are on the outside of the fold or roll when loading the power changing lens  104  into the injector  480 . Positioning the first side  400  and the flexible membrane  402  on the inside of the fold or roll can advantageously protect the flexible membrane  402  from damage upon entering or exiting the injector  480 . The power changing lens  104  is rotated 90 degrees out of the page and advanced into the eye and partially advanced out of the injector  480  in the cavity  160 . The periphery of the power changing lens  104  opposite the injector  480  is slid under the projection  344  opposite the incision I 2 . Thereafter the power changing lens  104  is further advanced out of the injector until portions of the circumference of the peripheral portion  408  adjacent to the projection  344  are exposed. Clockwise and counter clockwise rotations can allow the peripheral portion  408 , e.g., the outer circumference  409 , of the power changing lens  104  to move between the projections  344  and the corresponding support surfaces  170 . 
       FIG.  10 H  shows that gradual expansion of the power changing lens  104  in to the secured position in the posterior segment  163  of the cavity  160  of the haptic  124  as can occur with either the method of  FIG.  10 E- 1    or the method of  FIG.  10 E- 2   . A fully extended and secured power changing lens  104  is shown in  FIG.  1   . When assembled, a minimum distance  295  between a rearward surface of the optic coupler  411  facing the base lens  120  and an upper surface of the ring  292  surrounding the base lens  120  can be less than or equal to about 0.2 mm. For example, the minimum distance  295  between the rearward surface of the optic coupler  411  and the upper surface of the ring  292  surrounding the base lens  120 , as indicated at the arrows labeled G in  FIG.  2 C , can be greater than or equal to 0 mm and less than or equal to 0.05 mm, greater than or equal to 0.02 mm and less than or equal to 0.07 mm, greater than or equal to 0.05 mm and less than or equal to 0.09 mm, greater than or equal to 0.1 mm and less than or equal to 0.15 mm, greater than or equal to 0.12 mm and less than or equal to 0.2 mm, or any value in any range/sub-range defined by these values. Reducing the minimum distance  295  between the rearward surface of the optic coupler  411  facing the base lens  120  and the upper surface of the ring  292  surrounding the base lens  120  can advantageously reduce or prevent migration of cells through the channels  109  thereby reducing the risk of interlenticular PCO between the base lens  120  and the power changing lens  104 . The gap may permit some fluid flow  110  at indicated by dashed arrows but generally limit, reduce or prevent cell migration. Additionally, reducing the minimum distance  295  between the rearward surface of the optic coupler  411  facing the base lens  120  and the upper surface of the ring  292  surrounding the base lens  120  can advantageously reduce the risk of retinal detachment as a result of filling the capsular bag. 
     If needed, the power changing lens  104  and/or the projection  344  can be repositioned such that the power changing lens  104  is configured to be properly seated in the posterior segment  163 . Such repositioning can follow a visual inspection of the expanded power changing lens  104  and the expanded base member  102 . As discussed in connection with  FIG.  8    the ridge  372  can give clear visual cues as to whether the retention member  344 A is anterior of the first side  400  of the power changing lens  104  or is posterior of the second side  404  thereof. If the retention member  344 A is posterior of the power changing lens  104  the surgeon will reposition the peripheral portion  408  in the area of the retention member  344 A such that the first side  400  is posterior of the retention member  344 A. 
     Other forms of visual cues or indicia can be provided. For example, the ring  292  and/or other portions of the haptic  124  can be formed with a high contrast color, such as a blue color. One or more portions of, e.g., all of, the haptic  124  including the ring  292  can be formed of the materials discussed herein, including silicone materials, and can include a contrast forming component, such as a blue pigment or dye. For example, some silicone haptic materials may be blended with a color masterbatch material prior to curing, such color masterbatch including, but not limited to, the MED-4800 series from NuSil®, including MED-4800-7 (dark blue). Preferred pigments are substantially non-extractible from the cured material by water, saline or ocular fluids at about 37° C. The position of the ring  292  can be confirmed prior to insertion of the power changing lens  104 . The ring  292  can be confirmed to be centered on the visual axis of the eye, for example. The ring  292  can have a portion of a different color or with another visual cue that shows the orientation of a cylinder power. Different patterns can be provided on the membrane coupler  410  and on the anterior surface of the projection  344  of the lens retention portion  164 . For example the membrane coupler  410  can have a smooth finish and the anterior surface of the projection  344  can have a dull or matt finish. If there is an unbroken arc of smooth finish of more than 120 degrees the projection  344  can be confirmed to be posterior to the peripheral portion  408  of the power changing lens  104 . Instead of smooth and matt finishes, one of the peripheral portion  408  and the projection  344  can have hatching in one direction and the other can have hatching in another direction. Or, one of the peripheral portion  408  and the projection  344  can have a first color surface and the other can have a second color visually distinct from the first color. 
       FIG.  10 I  illustrates the power changing lens  104 A positioned within the base member  102  and the eye  50 . As described in reference to  FIGS.  4 C and  4 D , the rotational position feature  413  can be used to simultaneously verify orientation of the power changing lens  104 A about the optical axis and an axis perpendicular to the optical axis. For example, the array of dots of the rotational position feature  413  can be seen as an arrow that points in a clockwise direction indicating that the power changing lens  104 A is orientated with the first side  400  (anterior side) and flexible membrane  402  facing away from the base lens  120 , which is the correct orientation. The array of dots of the rotational position feature  413  also can visually indicate that the rotational position feature  413  is rotationally aligned about the optical axis to correspond to a transverse axis that falls along a prescribed orientation (e.g., 12 to 6 of a clock face) to match the unaccommodated power of the lens  104 A along that axis to the visual deficiency of the eye, e.g., for correction of astigmatism. If needed, the array of dots of the rotational position feature  413  can visually indicate an orientation corresponding to any perpendicular axis relative to the optical axis, such as a 2 to 8, 4 to 10, 5 to 11, or any other orientation (referring to a clock face to describe the transverse axes) as the power changing lens  104 A is rotated. As described above, the rotational position feature  413  can be a applied to a toric lens for confirming rotational positioning about the optical axis and can be beneficial for all types of lenses to confirm anterior-posterior orientation. 
     2. Systems for Intra-Ocular Assembly 
       FIG.  11    shows a portion of the injector  480 , which has been discussed above. The injector  480  includes the injector barrel  484 . The injector barrel  484  has a barrel tip  488  including an opening through which one or both of the base member  102  and the power changing lens  104  are injected into the eye  50 . 
     A inner barrel  504  can be located in the injector barrel  484 . The inner barrel  504  can house the power changing lens  104  in one embodiment. The inner barrel  504  can be centered on the longitudinal axis  500  and can be moveable along the longitudinal axis  500  independently of or relative to the injector barrel  484 . For example, the inner barrel tip  508  can be initially proximal of the barrel tip  488 . The inner barrel tip  508  can be advanced out of the barrel tip  488  during part of a procedure. 
     The  580  can include a plunger  492  that, as discussed above can be used to advance one or both of the base member  102  an the power changing lens  104  out of the injector  480 . The plunger  492  can include a plunger tip  496  that can be disposed proximal to one or both of the base member  102  and the power changing lens  104 . The plunger tip  496  can push the base member  102  or the power changing lens  104  out of the injector  480  into the eye. 
     In one approach the injector barrel  484  and the inner barrel  504  are separate instruments that can be mounted to the same or to different handles. The injector barrel  484  can have a proximal end that is mounted to such a handle and can be inserted through the incision I 1  or the incision I 2  to place the base member  102 . After the plunger  492  advances the base member  102  out of the injector  480  into the eye  50  the injector barrel  484  can be removed from the handle and the inner barrel  504  can be attached to the handle. When the injector barrel  484  and the inner barrel  504  are separate the inner barrel  504  is an inner barrel in that it delivers the inner device, e.g., the power changing lens  104 . The plunger  492  can be configured to be used with both the injector barrel  484  and thereafter with the inner barrel  504 . In other words, the plunger  492  can be part of the handle and can push both the base member  102  out of the injector  480  and can push the power changing lens  104  out of the inner barrel  504  after the injector barrel  484  has been removed and the inner barrel  504  mounted on the handle and the plunger  492  of the injector  480 . 
     In another approach the inner barrel  504  is mounted within the injector barrel  484 . The plunger  492  or the inner barrel  504  can be used to push the base member  102  out of the barrel tip  488 . Thereafter the plunger  492  and the inner barrel  504  can be advanced toward and in some cases out of the barrel tip  488 . The power changing lens  104  can then be urged by the plunger  492  out of the barrel tip  488 . 
       FIG.  11    shows one approach in which the base member  102  and the power changing lens  104  are both folded such that the concave portions of the folded structure are facing the same direction. The open side of the folded structure can be oriented in the injector  480  such that the open side faces anteriorly. This is advantageous for the method illustrated in  FIG.  10 F- 1   . 
     In another embodiment the base member  102  and the power changing lens  104  are folded and loaded in the injector  480  such that the concave portions of the folded structure face in opposite directions. The open side of the folded structure of the base member  102  can be oriented in the injector  480  such that the open side faces anteriorly. The open side of the folded structure of the base member  102  can be oriented in the injector  480  such that the open side faces posteriorly (as in the dashed lines). This is advantageous for the method illustrated in  FIG.  10 F- 2   . 
     The lumens of one or both of the injector barrel  484  and the inner barrel  504  can be treated to provide advantageous performance as taught by U.S. Pat. No. 7,037,312 which is hereby incorporated by reference herein in its entirety. For example, the lumen just proximal to the barrel tip  488  can be configured to gradually expand the base member  102 . In one approach the lumen just proximal to the barrel tip  488  is expandable to slowly expand the base member  102  prior to the base member  102  being fully expelled from the barrel tip  488 . In another approach the coefficient of friction of the lumen just proximal to the barrel tip  488  can be higher such that the injector naturally slows the egress of the base member  102 . In yet another approach the inner diameter of the injector barrel  484  can be reduced to elongate the base member  102  which in turn can reduce the speed at which the base member  102  is released. Similar approaches can be used for the inner barrel  504 . 
     As discussed in greater detail herein the base member  102  is configured to be inserted into the eye  50  through a small incision. This is facilitated by a number of hinge connections discussed below and by a reduction in material of the base member  102  where not needed. 
     II. Advantages and Other Applications of Two-Part Configurations 
     The accommodating IOL device  100  is modular which includes the idea that the base member  102  and the power changing lens  104  can be assembled separately. In one technique, separate assembly enables the base member  102  to be implanted first and the power changing lens  104  to be implanted subsequently, as discussed further below. Where the power changing lens  104  is assembled forward of the base member  102 , the power changing lens  104  also can be removed and replaced during the same procedure or in a subsequent procedure. Same procedure replacement can facilitate adjustment of the unaccommodated (e.g., distance) power. Such adjustment can enable a surgeon to address a surgical complication where the actual placement of the lens is different form the planned location of the lens and the difference causes the unaccommodated power to be too strong or too weak. This issue can be assessed at the time of the procedure by intraoperative assessment, such as using aberrometry. If the power is measured as too low, the initial power changing lens  104  can be exchanged for a power changing lens  104  with a higher unaccommodated power. If the power is measured as too high, the initial power changing lens  104  can be exchanged for a power changing lens  104  with a lower unaccommodated power. 
     In some cases, a difference arises between planned placement and post-procedure locations, e.g., after a period of recovery. The process of recovery can cause the base member  102  to shift from a planned or intraoperative position. If the shift is large enough even a perfect intraoperatively measured unaccommodated power can become noticeably too high or too low. After the recovery period, the initially placed power changing lens  104  can be removed and replaced with a power changing lens  104  having a power selected based on the final, healed position of the base member  102 . Without the ability to exchange the initially placed power changing lens  104  for a power changing lens  104  with more appropriate power, a larger number of patients would not achieve spectacle independence. 
     The separateness of the base member  102  and the power changing lens  104  provides additional benefits even when the base member  102  and power changing lens  104  are perfectly placed and matched. For instance, while the power changing lens  104  described below has been shown to provide excellent range of accommodation, improvements in design or changes in the patient&#39;s vision may make a lens upgrade advantageous. The power changing lens  104  can be removed and replaced with a higher performance lens or with a lens configured to address particular and in some cases changed vision needs of the patient. 
     Furthermore, the base member  102  provides a support for implanting second lenses that may not be fluid lenses. Some patients may prefer not to receive a biomimetic accommodating lens, such as with the power changing lenses described herein, but may prefer other types of lenses. The base member  102  can be implanted in such patients to enable such patients to receive a higher performance lens at a later date. For example,  FIGS.  4 E- 4 F  show examples of lenses that can be combined with the base member  102  to provide excellent outcomes short of biomimetic accommodation. 
       FIG.  4 E  shows a monofocal lens  104 B. The monofocal lens  104 B has a fixed optic  403 B, e.g., one that does not accommodate as described in reference to power changing lens  104 . The fixed optic  403 B has a set power that does not change in response to ocular forces. The monofocal lens  104 B can have a monolithic structure having a continuous body between an anterior surface and posterior surface of the monofocal lens  104 B and/or fixed optic  403 B. The monolithic structure enables the monofocal lens  104 B to be manufactured with a single molding step. In some aspects, the monofocal lens  104 B can be a monofocal toric lens to correct astigmatism. The fixed optic  403 B can have different optical powers along different perpendicular axes relative to the optical axis A, sometimes called toric axes, when the monofocal lens  104 B is also a toric lens. In other cases the monofocal lens  104 B has rotationally symmetrical optics. 
     The monofocal lens  104 B has a circular haptic  401 B. The circular haptic  401 B is centered around the optical axis A. The circular haptic  401 B is radially outward of an optical axis A. The circular haptic  401 B surrounds the fixed optic  403 B. The circular haptic  401 B can be placed under the lens retention portions  164  of the base member  102  to secure the monofocal lens  104 B to the base member  102 , such as shown in  FIG.  10 H . The monofocal lens  104 B can have, as described in reference to  FIGS.  4 A and  4 B , a visible color structure  405 B. The visible color structure  405 B can be the same as or similar to the visible color structure  409  discussed above. The visible color structure  405 B can be positioned in the periphery of the monofocal lens  104 B, such as in or on the circular haptic  401 B. The visible color structure  405 B can be positioned on an anterior surface of the circular haptic  401 B, posterior surface of the circular haptic  401 B, or between the anterior and posterior surface of the circular haptic  401 B, e.g., within the anterior-posterior thickness thereof. The visible color structure  405 B can be insert molded into the fixed optic  403 B or can be molded onto or into the circular haptic  401 B. The visible color structure  405 B can be used to visually verify orientation of the monofocal lens  104 B as described in reference to  FIGS.  4 A and  4 B . The visible color structure  405 B can be used to visually verify that the monofocal lens  104 B is secured by the lens retention portions  164  when monofocal lens  104 B is being positioned within the base member  102  as described in reference to  FIGS.  4 A and  4 B . In some aspects, the visible color structure  405 B reduces observable glare transmitted through the circular haptic  401 B, such as by one or more of reflecting, absorbing, or diffusing stray light. 
     The monofocal lens  104 B can have a rotational position feature  413 , that is the same as or similar to the rotational position feature  413  described in reference to  FIGS.  4 C and  4 D . The rotational position feature can be used to provide simultaneous confirmation of orientation about at least two axes, indicating rotational orientation about the optical axis A and rotational orientation about an axis that is perpendicular to the optical axis A. When the monofocal lens  104 B is a toric lens, the rotational orientation features  413  can be aligned with a specific transverse axis relative to the optical axis A, such as a toric axis, to properly orient the toric lens to correct astigmatism. For example, as described above, the rotational position feature  413  can visually indicate an orientation corresponding to any perpendicular axis relative to the optical axis A, such as a 2 to 8, 4 to 10, 5 to 11, or any other orientation (referring to a clock face to describe the transverse axes) as the monofocal lens  104 B is rotated about the optical axis A. 
       FIG.  4 F  shows a fixed multi-focal or multi-powered lens  104 C. The fixed multi-powered lens  104 C has a fixed optic  403 C that does not accommodate as described in reference to power changing lens  104 . The fixed multi-powered lens  104 C can have a monolithic structure having a continuous body between an anterior surface and posterior surface of the fixed multi-powered lens  104 C and/or fixed optic  403 C. The monolithic structure enables the fixed multi-powered lens  104 C to be manufactured with a single molding step. In some aspects, the fixed multi-powered lens  104 C can be a bifocal or trifocal lens, providing respectively two or three fixed focal points. In some aspects, the fixed multi-powered lens  104 C can be an extended depth of focus (EDOF or EDF) lens, having an elongated focal point to provide a range of powers. 
     The fixed multi-powered lens  104 C has a circular haptic  401 C. The circular haptic  401 C can be the same or similar to the circular haptic  401 B. The circular haptic  401 C can be placed under the lens retention portions  164  of the base member  102  to secure the fixed multi-powered lens  104 C to the base member  102 , such as shown in  FIG.  10 H . The fixed multi-powered lens  104 C can have, as described in reference to  FIGS.  4 A and  4 B , a visible color structure. The visible color structure can be the same as or similar to the other visible color structures described herein. The visible color structure can be used for orientating the fixed multi-powered lens  104 C as described herein. The fixed multi-powered lens  104 C can have a rotational position feature, that is the same as or similar to the other rotational position features described herein. The rotational position feature can be used to provide simultaneous confirmation of orientation about at least two axes, indicating rotational orientation about the optical axis A and rotational orientation about an axis that is perpendicular to the optical axis A. 
     The circular haptics  401 B,  401 C enable the lenses  104 B,  104 C to be compatible with a base member  102  that is configured to apply rotationally symmetrical compression to a power changing lens with a circular haptic when the base member is subject to rotationally symmetric compression, e.g., in the eye or in a bench-top test. The base member  102  is thus compatible with fixed optics such as the lenses  104 B,  104 C and can be upgraded to an accommodating IOL such as the power changing lenses  104 ,  104 A or another biomimetic IOL. By providing circular haptics the lenses  104 ,  104 A,  104 B,  104 C can be implanted in any rotational position within the base member  102  if a specific rotational position is not indicated. A circular haptic can facilitate re-positioning in the eye where a specific rotational position is indicated. For example, the lens  104 A can be situated in the base member  102  posterior of the tabs or other lens retention portion  164 . If the rotational position is to be adjusted, the circular haptics allow for the lens  104 A to be rotated in position, with the rotational position features  413  aligned with a specified axis. 
     Terminology 
     As used herein, the relative terms “proximal” and “distal” shall be defined from the perspective of the medical professional. Thus, proximal refers to the direction of the physician and distal refers to the direction of the eye when the surgeon is operating. 
     For expository purposes, the term “transverse” as used herein is defined as a direction generally perpendicular to the longitudinal axis of the assembly, unless otherwise specified. 
     Conditional language, such as “can,” “could,” “might,” or “may,” unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain embodiments include, while other embodiments do not include, certain features, elements, and/or steps. Thus, such conditional language is not generally intended to imply that features, elements, and/or steps are in any way required for one or more embodiments. 
     The terms “comprising,” “including,” “having,” and the like are synonymous and are used inclusively, in an open-ended fashion, and do not exclude additional elements, features, acts, operations, and so forth. Also, the term “or” is used in its inclusive sense (and not in its exclusive sense) so that when used, for example, to connect a list of elements, the term “or” means one, some, or all of the elements in the list. 
     The terms “approximately,” “about,” “generally,” and “substantially” as used herein represent an amount close to the stated amount that still performs a desired function or achieves a desired result. For example, the terms “approximately,” “about,” “generally,” and “substantially” may refer to an amount that is within less than 10% of the stated amount, as the context may dictate. 
     The ranges disclosed herein also encompass any and all overlap, sub-ranges, and combinations thereof. Language such as “up to,” “at least,” “greater than,” “less than,” “between” and the like includes the number recited. Numbers preceded by a term such as “about” or “approximately” include the recited numbers. For example, “about four” includes “four” 
     Any methods disclosed herein need not be performed in the order recited. The methods disclosed herein include certain actions taken by a practitioner; however, they can also include any third-party instruction of those actions, either expressly or by implication. For example, actions such as “distally moving a locking element” include “instructing distal movement of the locking element.” 
     Although certain embodiments and examples have been described herein, it will be understood by those skilled in the art that many aspects of the humeral assemblies shown and described in the present disclosure may be differently combined and/or modified to form still further embodiments or acceptable examples. All such modifications and variations are intended to be included herein within the scope of this disclosure. A wide variety of designs and approaches are possible. No feature, structure, or step disclosed herein is essential or indispensable. 
     Some embodiments have been described in connection with the accompanying drawings. However, it should be understood that the figures are not drawn to scale. Distances, angles, etc. are merely illustrative and do not necessarily bear an exact relationship to actual dimensions and layout of the devices illustrated. Components can be added, removed, and/or rearranged. Further, the disclosure herein of any particular feature, aspect, method, property, characteristic, quality, attribute, element, or the like in connection with various embodiments can be used in all other embodiments set forth herein. Additionally, it will be recognized that any methods described herein may be practiced using any device suitable for performing the recited steps. 
     For purposes of this disclosure, certain aspects, advantages, and novel features are described herein. It is to be understood that not necessarily all such advantages may be achieved in accordance with any particular embodiment. Thus, for example, those skilled in the art will recognize that the disclosure may be embodied or carried out in a manner that achieves one advantage or a group of advantages as taught herein without necessarily achieving other advantages as may be taught or suggested herein. 
     Moreover, while illustrative embodiments have been described herein, the scope of any and all embodiments having equivalent elements, modifications, omissions, combinations (e.g., of aspects across various embodiments), adaptations and/or alterations as would be appreciated by those in the art based on the present disclosure. The limitations in the claims are to be interpreted broadly based on the language employed in the claims and not limited to the examples described in the present specification or during the prosecution of the application, which examples are to be construed as non-exclusive. Further, the actions of the disclosed processes and methods may be modified in any manner, including by reordering actions and/or inserting additional actions and/or deleting actions. It is intended, therefore, that the specification and examples be considered as illustrative only, with a true scope and spirit being indicated by the claims and their full scope of equivalents.