Patent Publication Number: US-8985765-B2

Title: Adjustable spectral transmittance eyewear

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a Continuation of application Ser. No. 13/009,417, filed on Jan. 19, 2011, which is a Continuation-in-Part of copending U.S. Nonprovisional application having Ser. No. 12/829,878, filed on Jul. 2, 2010, which is a Continuation-in-Part of U.S. Nonprovisional application having Ser. No. 11/514,822, issued as U.S. Pat. No. 7,828,434, filed on Aug. 31, 2006. The entireties of the aforementioned applications are incorporated by reference herein. 
    
    
     BACKGROUND 
     Athletic achievement in both individual and team sports continues to improve. Scientifically proven nutrition and training regimes are available to athletes at all levels from personal trainers, specialized coaches, and Internet-based trainers and training programs. In addition, athletic equipment, footwear, and apparel have been developed to offer athletes superior performance as well as a stylish appearance and comfort. Injury treatment has also improved, and some serious injuries that were previously career ending can be treated with techniques that permit nearly complete recovery with only a brief period of rehabilitation. Thus, athletes are fitter, stronger, better trained, better equipped, and better cared for than ever before. 
     While athletic performance is a direct function of an athlete&#39;s physical condition, many sports demand that the athlete accurately perceive and respond to the position and motion (such as velocity, acceleration, deceleration) of teammates, competitors, and sport-specific objects such as footballs, basketballs, baseballs, pucks, or other objects. For example, successful hitters in baseball or football quarterbacks appear to have higher visual acuity than others, at least with respect to situations encountered in their sports. In order to increase personal performance, athletes have become interested in vision training as another avenue toward enhanced performance. For example, hitters want to improve their vision so at to be able to see the seams on a 90+ mph fastball. Thus, athletes are targeting achieving superior visual dexterity to complement their physical dexterity. Unfortunately, available methods for vision training and assessment are generally not well tailored to the specific skills needed for a selected sport, nor are the methods readily configurable to provide the varied training that can be required. Accordingly, improved methods and apparatus are needed for vision training. 
     SUMMARY 
     Embodiments of the present invention relate to eyewear having an electrically switchable spectral transmittance lens or lenses. The eyewear is comprised of a first lens having electrically variable spectral transmittance that is able attenuate light as perceived by a wearer of the eyewear. The eyewear also is comprised of a second lens having electrically variable spectral transmittance that is able to attenuate light perceived by the wearer. The electrically variable spectral transmittance of the first lens and the second lens is controlled by a lens driver of the eyewear. The lens driver is functional to adjust a duty cycle and a frequency of the variable spectral transmittance of the first lens from a first spectral transmittance for a first duration and a second spectral transmittance for a second duration. The eyewear may also be comprised of a frame configured to retain the first lens and the second lens in a position relative to the wearer. The eyewear may also be comprised of a receiving module effective to receive a remote signal for use as an input to the eyewear. 
     This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       Illustrative embodiments of the present invention are described in detail below with reference to the attached drawing figures, which are incorporated by reference herein and wherein: 
         FIG. 1  illustrates a representative example of vision training eyewear in accordance with embodiments of the present invention; 
         FIG. 2  illustrates a vision training system that includes vision training eyewear in accordance with embodiment of the present invention; 
         FIG. 3  illustrates vision training eyewear in accordance with embodiments of the present invention; 
         FIG. 4  illustrates a temple piece for vision training eyewear that includes controls for selecting a level of visual difficulty provided by the eyewear in accordance with embodiments of the present invention; 
         FIG. 5  illustrates left and right lenses that include a plurality of zones in accordance with embodiments of the present invention; 
         FIGS. 6-7  illustrate a clear state and a dark state, in phase, for the lenses of  FIG. 5 , in accordance with embodiments of the present invention; 
         FIGS. 8-9  illustrate a clear state and a dark state, out of phase, for portions of the lens of  FIG. 5  in accordance with embodiments of the present invention; 
         FIG. 10  illustrates a portion of a representative temple piece for vision training eyewear that includes controls for selection of rows and columns of zones in accordance with embodiments of the present invention; 
         FIG. 11  illustrates curved eyewear in accordance with embodiments of the present invention; 
         FIG. 12  illustrates curved eyewear from an exploded posterior perspective in accordance with embodiments of the present invention; 
         FIG. 13  illustrates a portion of a curved eyewear frame having a curved channel in accordance with embodiments of the present invention; 
         FIG. 14  illustrates a front perspective view of a curved eyewear in accordance with embodiments of the present application; 
         FIG. 15  illustrates a curved lens effective for manipulating perceived light by two eyes of a human wearer in accordance with an embodiment of the present invention; 
         FIG. 16  illustrates a top view of a curved eyewear in accordance with embodiments of the present invention; 
         FIG. 17  illustrates an exemplary curved lens defined by a curve in accordance with embodiments of the present invention; 
         FIG. 18  illustrates an exemplary curved lens defined by another set of curves in accordance with embodiments of the present invention; 
         FIG. 19  illustrates a clear state and dark state duration corresponding to an exemplary repetitive cycle, in accordance with embodiments of the present invention; 
         FIG. 20  illustrates a clear state and dark state duration corresponding to an exemplary repetitive cycle, which is an inverse of that provided by  FIG. 19 , in accordance with embodiments of the present invention; 
         FIG. 21  illustrates a clear state and dark state exemplary repetitive cycle having a constant duty cycle and a varied frequency with each level, in accordance with embodiments of the present invention; and 
         FIG. 22  illustrates a clear state and dark state exemplary repetitive cycle having a varied duty cycle and a constant frequency with each level, in accordance with embodiments of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     The subject matter of embodiments of the present invention is described with specificity herein to meet statutory requirements. However, the description itself is not intended to limit the scope of this patent. Rather, the inventors have contemplated that the claimed subject matter might also be embodied in other ways, to include different steps or combinations of steps similar to the ones described in this document, in conjunction with other present or future technologies. 
     Embodiments of the present invention relate to eyewear having an electrically switchable spectral transmittance lens or lenses. The eyewear is comprised of a first lens having electrically variable spectral transmittance that is able attenuate light as perceived by a wearer of the eyewear. The eyewear also is comprised of a second lens having electrically variable spectral transmittance that is able to attenuate light perceived by the wearer. The electrically variable spectral transmittance of the first lens and the second lens is controlled by a lens driver of the eyewear. The lens driver is functional to adjust a duty cycle and a frequency of the variable spectral transmittance of the first lens from a first spectral transmittance for a first duration and a second spectral transmittance for a second duration. The eyewear may also be comprised of a frame configured to retain the first lens and the second lens in a position relative to the wearer. 
     Accordingly, in one aspect, the present invention provides vision training eyewear. The eyewear are comprised of a first lens having electrically variable spectral transmittance that is able attenuate light as perceived by a wearer of the vision training eyewear, wherein the electrically variable spectral transmittance is controlled by a lens driver. The eyewear also are comprised of a second lens having electrically variable spectral transmittance able to attenuate light as perceived by the wearer, wherein the lens driver controls spectral transmittance of the second lens. The lens driver is functional to adjust a duty cycle and a frequency of the variable spectral transmittance of the first lens from a first spectral transmittance for a first duration and a second spectral transmittance for a second duration. The eyewear is also comprised of a frame configured to retain the first lens and the second lens; and 
     In another aspect, the present invention provides a vision training system. The vision training system is comprised of eyewear having a first lens and a second lens, wherein the first lens and the second lens have electrically variable spectral transmittance to obscure a portion of a trainee&#39;s field of view, wherein variations of the electrically variable spectral transmittance of the first lens and of the second lens are performed in phase. The vision training system also is comprised of a lens driver configured to control a duty cycle and a frequency of the electrically variable spectral transmittance of the first lens and the second lens. The duty cycle of the electrically variable spectral transmittance of the first lens and the second lens is adjustable to vary a percentage of a cycle for an obscured state having a first duration or a percentage of the cycle for an un-obscured state having a second duration. The frequency of the electrically variable spectral transmittance of the first lens and the second lens is adjustable to vary a number the cycles in a period of time, such that the frequency is adjustable at 15 Hz and less. 
     A third aspect of the present invention provides vision training eyewear. The eyewear are comprised of a first lens having electrically variable spectral transmittance that is functional to attenuate light at a first spectral transmittance state having a first duration, wherein the electrically variable spectral transmittance is controlled by a lens driver. The eyewear is also comprised of a second lens having electrically variable spectral transmittance that is functional to attenuate light at the first spectral transmittance state having the first duration, wherein the electrically variable spectral transmittance is controlled by the lens driver. The lens driver is configured to receive a frequency and a duty cycle, such that the lens driver controls the first duration of the first lens and the second lens based on one of the frequency or the duty cycle. 
     Having briefly described an overview of embodiments of the present invention, an exemplary operating environment suitable for implementing embodiments hereof is described below. 
     As used herein, the singular forms “a,” “an,” and “the” include the plural forms unless the context clearly dictates otherwise. Additionally, the term “includes” means “comprises.” The described systems, apparatus, and methods should not be construed as limiting in any way. Instead, the present disclosure is directed toward all novel and nonobvious features and aspects of the various disclosed embodiments, alone and in various combinations and sub-combinations with one another. The disclosed systems, methods, and apparatus are not limited to any specific aspect or feature or combination thereof, nor do the disclosed systems, methods, and apparatus require that any one or more specific advantages be present or problems be solved. 
     Although the operations of some of the disclosed methods are described in a particular, sequential order for convenient presentation, it should be understood that this manner of description encompasses rearrangement, unless a particular ordering is required by specific language set forth below. For example, operations described sequentially may in some cases be rearranged or performed concurrently. Moreover, for the sake of simplicity, the attached figures may not show all the various ways in which the disclosed systems, methods, and apparatus can be used in conjunction with other systems, methods, and apparatus. 
     Variable spectral transmittance lenses for use with eyewear are provided. Representative eyewear comprise at least a first lens defining a zone having selectable optical transmittance, and a frame configured to retain the first lens and to support the lens in front of a wearer&#39;s eye. One or more zone connection conductors are coupled to the first lens and adapted to provide control signals to the zone(s). In typical examples, the eyewear further comprise a second lens retained in the frame so as to position the first lens and the second lens in front of respective eyes of the wearer. Zone connection conductors are coupled to the first lens and the second lens. In other examples, a lens driver is secured to the frame and coupled to the first and second lenses so as to provide control signals to the first and second lenses. In some examples, the lenses comprise a flexible liquid crystal device, and the flexible liquid crystal device is secured to a lens substrate. The lens has an anterior surface and a posterior surface in an as worn position. 
     In additional examples, the eyewear comprises a level selector configured to adjust a level of visual difficulty provided by one or both lenses. In some examples, the level of difficulty is associated with a duration during which a lens is light attenuating. 
     In one example, eyewear comprise first and second lenses defining respective pluralities of zones and retained in a frame so as to position the first lens and the second lens in front of respective eyes of a wearer. At least one zone connection conductor is coupled to the zones of the first and second lenses, and is configured to receive a control signal so as to selectively vary an optical transmission of sets of zones. A lens driver can be secured to the eyewear (or provide separately) and configured to actuate a first set of zones on the first lens and a second set of zones of the second lens to alternately substantially transmit and substantially attenuate a light flux directed through the first lens and the second lens. The eyewear also includes a pattern selector configured to select the first set of zones and the second set of zones and a user input for selection of an interval during which the first set of zones and the second set of zones are substantially attenuating. The zones of the first lens and the second lens can be arranged in rows and columns, and the pattern selector can include a row selector and a column selector configured to select one or more rows and/or one or more columns of zones in each lens for inclusion in the first set of zones and the second set of zones. 
     Vision training systems comprise eyewear configured to selectively obscure a portion (or all) of a trainee&#39;s field of view, and a lens driver configured to temporally vary the obscured portion of the trainee&#39;s field of view. A computer readable medium such as random access memory (RAM) can be configured for use by the lens driver to vary the obscured portion of the field of view by keeping a transmissive state duration approximately constant and altering a substantially non-transmissive state duration. Similarly, the lens driver may further obscure a portion of the field of view by keeping the substantially non-transmissive state duration approximately constant and altering a transmissive state duration. Further yet, it is contemplated that both the transmissive and the non-transmissive state durations may be altered by the lens driver. 
     Referring to  FIG. 1 , training eyewear  100  includes a frame  102  that is adapted to retain a first lens  104  and a second lens  106 . In some examples, the lenses  104 ,  106  can provide optical power such as typically used to correct nearsightedness, farsightedness, astigmatism, or other visual defects, but the lenses  104 ,  106  can also be configured to provide little or no optical power for such corrections. Consequently, as used herein, the term lens refers to both a plano (i.e., non-corrective) and a powered lens. The lenses  104 ,  106  include respective pluralities of segments or zones such as representative zones  108 ,  110  that are labeled in  FIG. 1 . For convenience in the following description, all zones of the lenses  104 ,  106  are referred to occasionally as zones  108 ,  110 , respectively. The zones  108 ,  110  have optical properties that can be adjusted, selected, or established with, for example, electrical signals applied to the segments (zones). For example, the segments can be defined with liquid crystal materials such as polymer dispersed liquid crystals, nematic liquid crystals, cholesteric liquid crystals, or other electrically switchable optical materials that are situated between transparent conductive layers that are patterned to produce selected segment geometries. Specific examples of liquid crystal materials may include, but not be limited to, twisted nematic, in-plane switching, advanced fringe field switching, vertical alignment, and blue phase mode. Liquid crystal materials are convenient due to their relatively low drive voltages, but other electro-optical materials such as, for example, electrophoretic materials or so-called “electronic inks” that have been developed for flexible flat panel displays can be used. 
     As used herein, the concept of zones may imply a singular zone or a plurality of zones. For example, a first lens through which a first eye of a user perceives light may define a first single zone. Additionally, a second lens through which a second eye of the user perceives light may define a second (but yet still single) zone. Therefore, a lens driver in this example may control both the first zone (first lens as a whole) and the second zone (second lens as a whole). 
     The term “spectral transmittance” is used herein to describe a perceived state of light as transmitted by a material. For example, obscuring, attenuating, diffusing, scattering, and blocking may alter a spectral transmittance of a material. Further, an exemplary aspect utilizes variable spectral transmittance to alter a percentage of light as perceived by a user. A percentage of light as perceived by a user may apply to visible light in general, or to particular frequencies of light when explicitly indicated. Further, a material having variable spectral transmittance may diffuse light so as to blur or otherwise reduce focus as perceived by a user. Diffusing of light may reduce strain on a user&#39;s pupil when adjusting from changes in light intensity from an obscured state to a non-obscured state than a blocking mechanism. Therefore, concepts of obscuring, blocking, diffusing, attenuating, and the like may be used interchangeably throughout as concepts of spectral transmittance. 
     While the eyewear of  FIG. 1  includes separate lenses for a left eye and a right eye, in other examples a single lens pane can be provided that is situated appropriately with respect to each eye. In some examples, a lens or portions of a lens pane for one eye is configured to substantially obscure vision through the associated eye. Such obscuration can be achieved with, for example, opaque, translucent, or other light blocking and/or light scattering lens regions or lens pane regions. In some examples, one of the lenses or lens pane regions can be patterned so as to be selectively switchable to be substantially obscuring or substantially transparent without being configured to display patterned obscurations. For example, a lens as a whole may be either obscuring or transparent rather than mere portions/zones of a lens. 
     The zones  108 ,  110  can be electrically coupled to a lens driver that is secured to, for example, a temple piece  112  or other portion of the eyewear, or that is independently locatable so that the driver can be secured to, for example, an armband, a pocket, or a waistband as may be convenient. A lens driver can provide electrical control signals that actuate some or all of the zones to become substantially opaque, transparent, or otherwise vary a spectral transmittance. The zones/lenses can be configured to provide electrically variable spectral transmittances, so that a spectrum of transmitted light varies with the applied electrical drive. Stated differently, adjustable spectral transmittance is adjusting, along a spectrum of light intensity, an amount of light that is conveyed through a lens. Therefore, adjusting the spectral transmittance may range from completely transparent (no electronic adjustment/full electrical adjustment) to substantially obscuring (full electronic adjustment/no electrical adjustment). A pattern or arrangement of zones and a manner of actuation can be selected by the lens driver with a pattern generator or controller that is provided as part of the lens driver or provided separately. A remote lens driver or pattern generator can be coupled to the eyewear with an electrical cable. In some examples, patterns can be transmitted wirelessly to the eyewear so that a trainer can select an appropriate zone actuation pattern without interfering with the wearer&#39;s activity. Further, duty cycles, durations, and other temporal aspects may be transmitted wirelessly to the eyewear by the trainer (or any party) without interfering with the wearer&#39;s activity. 
     The zones  108 ,  110  can be activated in a variety of zone actuation patterns based on a geometrical arrangement of activated zones, a temporal sequence in which zones are actuated, a rate of zone actuation, a progression of zone patterns, or other spatially and/or temporally variable or fixed configurations. For example, some or all zones can be activated to obscure a wearer&#39;s vision in a temporal sequence so that initially the relative duration of obscuration is small and the duration of the obscuration gradually increases. Further, a duty cycle and/or a frequency of a lens (or lenses) may be adjusted as part of a temporal sequence. 
     Zones or selected groups of zones (e.g., lens portions) can be selected to obscure portions of a wearer&#39;s field of view. For convenience, an arrangement of one or more zones is referred to herein as an obscuration pattern. An extent to which a zone or an obscuration pattern modulates light transmission or light emission is referred to as an obscuration intensity. A series of one or more activated obscuration patterns is referred to as a sequence. A rate at which an activation pattern or patterns in a sequence are activated can be referred to as a strobe rate. A strobe rate can be defined by a frequency. A frequency is a number of cycles in a defined duration. For example, a cycle may be defined as a transparent state and an obscured state. A frequency then may be a number of cycles per second. A duty rate is a percentage of a cycle that is a particular state. For example, a duty rate may define a percentage of a cycle that is transparent. Conversely, a duty cycle may define a percentage of a cycle that is obscured. 
     In some examples, the same or similar patterns and sequences are directed to a left lens and a right lens, but different patterns, sequences, and timings can be provided to the different lenses. Sequences and patterns can also be applied to lenses with different phases. For example, a pattern can be activated at a left lens, and then, upon partial or complete deactivation of the pattern, a corresponding or different pattern can be activated at a right lens. In some examples, actuation of patterns on a left and right lens is substantially simultaneous (in phase), while in other examples one is activated only when the other is deactivated (out of phase). 
     A representative vision training system that includes switchable eyewear  202  (also referred to herein as eyewear and/or curved eyewear) and a control system  204  is illustrated in  FIG. 2 . The control system  204  is coupled to the eyewear  202  with a flexible electrical cable  206  that is configured to communicate electrical signals to and from the eyewear  202 . The eyewear  202  includes temple pieces  208 ,  209 , lenses  210 ,  211  and a bridge  212 . The lenses  210 ,  211  are typically retained by lens rims defined in a frame front that also includes the bridge  212 , but other eyewear configurations such as rimless eyewear can be used. A light sensor  214  can be situated in or on the bridge  212  or other location on the eyewear  202 . As shown in  FIG. 2 , the lenses  210 ,  211  include zones  216 ,  217 ,  218  and  219 ,  220 ,  221 , respectively, but more zones or different arrangements of zones can be provided. 
     The control system  204  includes a remote lens driver/decoder  234  that is adapted to provide suitable electrical signals to the lens zones  216 - 221 . In some examples, the lens driver  234  is configured to provide electrical signals by selectively addressing the zones row by row or column by column as is customary in addressing liquid crystal display panels. For lenses having only a few zones, each zone can be individually addressable with dedicated conductors. It can be convenient to provide signal decoding or distribution on the eyewear to simplify electrical connections to the control system  204  to avoid, for example, the need to provide multiple row and column signals over the cable  206 . In some examples, the control system  204  or some portions thereof are secured to or integrated into the bridge, temple pieces, or other portions of the eyewear  202 . In  FIG. 2 , a frame-mounted decoder  235  is situated on the left temple piece  209 . In other examples, the control system or portions thereof are configured for attachment to an eyewear user&#39;s clothing, body, or equipment. 
     The control system  204  can also include a memory  222  and a pattern generator/sequencer  224 . The memory  222  can be configured to store obscuration patterns and/or temporal sequences for activation of variable spectral transmittance lenses. Further, it is contemplated that the memory  222  could record training data corresponding to the durations and sequences in which the eyewear has been used in training sessions. The pattern generator/sequencer  224  can be configured to determine pre-established pattern sequences and/or obscuration patterns for use. In addition, patterns and/or sequences can be modified or adapted in response to, for example, input commands or other use inputs received via a user interface  226 . 
     In some examples, the user interface  226  is configured for selection of patterns and/or sequences, and can include one or more user controls such as knob, sliders, push buttons, conductive inputs, or other input devices. Typical adjustments relate to a rate at which a particular pattern is repeated or a rate at which a sequence of patterns is provided. For example, an obscuration pattern can be strobed at a high rate (greater than about 30 Hz) so that the strobing is noticed by the wearer primarily as a reduced transmitted light intensity. Alternatively, a pattern can be strobed at a rate at which the wearer notices an interval in which her vision is impeded. Typically rates less than about 5 Hz are associated with noticeable obscurations. A constant strobe rate, in an exemplary aspect, may be unnecessary. For example, a strobe rate can vary from a high rate to a low rate so that the visual obscuration presented to the wearer increases, increasing the visual demands on the wearer. Such variable frequency drive can be referred to as a “chirped” drive. 
     Additional inputs able to be received include a duty cycle input, For example, a user or other party may desire to change a percentage of time that one or more lenses/zones are in a given spectral transmittance state. In an exemplary embodiment, a user may desire to increase a percentage of time that the one or more lenses (or one or more zones) of the eyewear are in a substantially obscuring state. In the alternative, a user may desire to alter a percentage of time that one or more lenses (or one or more zones) are in a substantially transparent state. These are all examples of duty cycle inputs that may be received. 
     An additional input that may be received is directed to a frequency at which one or more lenses (or one or more zones) strobe. For example, a user (or third party) may provide an input indicating that a frequency of the strobe rate is to be either increased, decreased, are set to one or more patterns/sequences. Therefore, it is contemplated that a cycle from a first state to a second state for a lens of the eyewear may be adjusted, through received inputs, to alter a percentage of time in the first state, a percentage of time in a second state, and a number of cycles in a time period. Additional inputs are also contemplated to effectuate any of the functionalities and/or features discussed herein. 
     An external input/output connection  228  such as a Universal Serial Bus (USB) or other communication connection can be provided. Such a connection can be coupled to the pattern generator/sequencer  224  to provide or adjust patterns and sequences available for use. Additional patterns and sequences can also be received from the connection  228  for storage in the memory  222 . In some examples, a vision training schedule can be transferred to the control system  204  for one or more future training sessions. The training schedule can be transferred from the athlete&#39;s computer, or forwarded to the athlete from a trainer over a network such as the Internet. In addition, data concerning usage can be delivered to the connection  228  for inclusion in, for example, a record of an athlete&#39;s training schedule. Such a record can be forwarded to a coach or trainer via a network such as the Internet or using email or instant messaging. The USB connection is also contemplated as a port useable or charging one or more power sources. For example, a rechargeable battery may be utilized as a power source to operate the variable spectral transmittance lenses/zones. In this example, by way of the USB, a sufficient source of energy may be provided to charge the battery. 
     A display controller  230  is configured to control a display portion  232  of the lens  211 . The display portion  232  typically includes a plurality of display pixels so that information concerning current eyewear or training settings or conditions can be presented in a user&#39;s field of view. In some examples, the display portion includes a single pixel that can be strobed or otherwise actuated to indicate eyewear status. For example, a rapidly strobing display portion  232  can indicate a pattern rate or a duration of a training session. 
     The light sensor  214  is in communication with a sensor processor  238  that can provide an indication of, for example, ambient lighting in an environment in which the eyewear  202  is situated, or direct lighting received by the eyewear  202 . Obscuration patterns, sequences, and intensities can be varied based on the indication. The processor  238  generally includes an amplifier or buffer that can receive an electrical signal from the light sensor  214  and provide an output signal indicative of light received. For example, an overall illumination level can be established so that, for example, a wearer&#39;s eyes receive a similar light flux regardless of ambient illumination conditions. 
     Differing obscuration patterns and sequences can be supplied to the left and right lenses. In some examples, vision from a single eye is to be trained, and only the corresponding lens is used. In other examples, the lenses are selected at random intervals to serve as distractions such as might be encountered due to, for example, fan motion, or other regular or irregular movements at a sporting event. 
     Accordingly, any number of components may be employed to achieve the desired functionality within the scope of embodiments of the present invention. Although the various components of  FIG. 2  are shown with lines for the sake of clarity, in reality, delineating various components is not so clear, and metaphorically, the lines would more accurately be grey or fuzzy. Further, although some components of  FIG. 2  are depicted as single blocks, the depictions are exemplary in nature and in number and are not to be construed as limiting. 
       FIG. 3  illustrates representative vision training eyewear  300  that includes a temple piece  302 , a frame front  304 , and a lens  306 . The lens  306  includes zones such as representative zone  308 . A control switch  310  is provided and is electrically coupled to the lens zone with an interconnect  312  that is included in the frame front. The control switch  310  can be adapted to activate the zones or select patterns or pattern sequences. For example, the switch  310  can include a rotating portion that can select pattern strobe rate, and a push mechanism for turning the eyewear on and off. 
     Lenses for vision training eyewear can include a lens substrate, such as a lens blank of glass, polycarbonate, acrylic, or other suitable optical material. The substrate can be configured to define both a left and a right lens or separate substrates can be used for each. Substrates can be tinted or colored to control total transmittance and/or provide a predetermined spectral frequency transmittance, or can be made of photochromic materials. A lens substrate typically has a posterior surface (facing the wearer) and an anterior surface (facing away from the wearer) in an as worn position. Curvatures and centers of curvature of one or both of these surfaces can be selected to provide a preferred optical correction, or to be substantially optically neutral. Further, curvatures may be provided to supply sufficient “wrap” or peripheral vision coverage. For convenience, a positive curvature is defined as a curvature whose center is on a posterior side of a lens substrate in an as worn position. Curvatures of the surfaces typically are selected to be between about 0 diopter and +14 diopters. 
     Diopter, also sometimes referred to as diopter, can be a measurement of curvature equal to the reciprocal of the radius of the curve measured in meters. For example, a circle with a radius of ½ meter (i.e., diameter of 1 meter) has a curvature of two diopters. Consequently, as indicated previously, exemplary embodiments include a lens having a curvature between 0 and +14 diopters, which is equivalent to a lens having a curvature that is defined by a diameter up to and possibly greater than 1/7 meter (0.1428 meter) (i.e., radius possibly greater than 1/14 meters). However, it is understood that the curvature of the lens as a whole or portions of a lens may be defined by a diameter such as between 120 and 200 millimeters (i.e., 0.12 to 0.2 meters). In an additional exemplary embodiment, the curvature of a lens may also range between 130 and 180 millimeters in diameter. Or, in an additional embodiment, it is contemplated that the curvature of a lens ranges from 130 to 140 millimeters in diameter in at least portions of the lens. 
     Vision training lenses also may include a zone-switchable optical modulator that can be conformed to or bonded to an anterior surface or a posterior surface of the lens substrate. Such optical modulators can be flexible for attachment to surfaces having optical curvatures of 4 diopters or more. Optical modulators can be bonded to both surfaces if desired. The modulator generally includes an optically active (i.e., switchable) area and an interconnection portion (typically at a perimeter) that is adapted to receive control signals and deliver the control signals to the switchable zones directly or to a zone driver decoder that establishes, for examples, appropriate row and column conductor signals for matrix addressing. Flexible liquid crystal-based modulators are convenient. 
     While frame-based eyewear can be convenient for general use and activity-specific training, activity-specific eyewear, visors, face shields, or protective shields can be similarly configured. For examples, obscuration zones can be provided on a face shield adapted for a football, hockey, or lacrosse helmet or other head protector. Goggles and facemasks for racquet sports, lacrosse, and baseball can also be configured to include vision shield portions on which pluralities of switchable zones can be defined. 
     The examples include obscuration patterns or zones that block or partially block a portion of a field of view. However, other kinds of obscuration patterns and obscuration zones can be used. For example, light emitting zones can be provided so that a wearer&#39;s field of view is presented with regions of increased light emission that tend to obscure view. Such emission zones can be configured to provide temporally varying light emission, including spectrally varying light emission. If desired, such light emission can also be configured to have a spatially and/or temporally varying polarization. The zones can occupy substantially the entire area of a lens, or can be configured to occupy only a small portion of the lens area. For examples, lenses that include opaque light emission regions can be configured so that the lenses are largely transparent. Accordingly, light attenuating zones and/or light emissive zones can be provided. 
       FIG. 4  illustrates a temple piece  400  for exemplary vision training eyewear. The temple piece  400  includes a power button  402  and level adjust buttons  404 ,  406  that can be used to decrease or increase the visual challenge (i.e., the level of difficulty) that the eyewear provides. These buttons are located on the temple piece  402  for convenient adjustment while in use. The power button  402  can be configured to initiate and terminate operation of the vision training eyewear. In addition, the power button  402  can be configured so that pressing the button can be used to toggle among strobing of a right lens only, strobing of a left lens only, or strobing of both lenses. The power button  402  can also be configured to sequence through a predetermined menu of zone patterns or sequences, but it can be more convenient to provide an additional selection button to facilitate these or other user adjustments. The level adjust button  404  can be configured so that pressing the level adjust button  404  increases a difficulty level until a maximum available difficulty level is reached at which point additional button presses may have no effect. Operation of the level adjust button  406  can be similar at a minimum difficulty level. 
     In an additional exemplary embodiment, a subsequent activation of a mode button that is currently set to an extreme (i.e., highest or lowest level) cycles to the next extreme (e.g., cycle of difficulty levels 1, 2, 3, 4, 5, 6, 7, 8, 1, 2, 3 . . . ). For example, if a difficulty level is currently set to a highest extreme (e.g., level 8); a subsequent activation (e.g., depressing, manipulation, and wearer provided feedback) of a mode button causes the difficulty to switch to the lowest level of difficulty (e.g., level 1). 
     Additionally, it is contemplated that vision training eyewear include fewer or more controls (e.g., buttons). For example, when vision training eyewear is intended to be used solely for 3D viewing purposes, a difficulty selection control may not be utilized. In this example, the flicker rate/strobe rate may be controlled by an external controller (e.g., synchronization signal provided by a display device). Similarly, controls may be limited to a power (e.g., on/off) control and a mode control that cycles through difficulty levels or modes of operation (as discussed above). Therefore, it is contemplated that one or more controls may be implemented in various embodiments of the present invention. 
       FIG. 5  illustrates an arrangement of zones in a left lens  502  and a right lens  504  that can be controlled with a temple piece such as that of  FIG. 4 . As shown in  FIG. 5 , the left lens  502  and the right lens  504  are formed as a unitary lens assembly  500 , but can be provided separately as well. A display region  510  is also provided to permit communication of eyewear settings to the user. As shown in  FIG. 5 , a seven segment display is convenient. The lenses  502 ,  504  include representative zones  506 ,  508 , respectively. The remaining zones are unlabeled in  FIG. 5 . In some examples, the zones provide variable light attenuation. While the zones can be controlled to be substantially clear, substantially opaque, or have intermediate values of light transmission, example operation of eyewear that includes the temple piece  402  and the lenses  502 ,  504  is described with zones that are referred to as configurable to be in a “clear” state or a “dark” state. 
     Operation of the lenses of  FIG. 5  is illustrated in  FIGS. 6 ,  7 ,  8 , and  9 . When the lenses are powered on using the power button  404 , an initial or default difficulty level may be displayed in the display region  510  and the lenses remain in the clear state (or dark state). The default difficulty level can be an easiest level and assigned an indicator of “1” that is displayed when the lenses are powered on. After a brief interval (for example, 2-10 sec), the zones of the lenses  502 ,  504  begin to strobe at a rate associated with the initial difficulty level, and the display  510  can be switched off. Strobing of one or both lenses can be set as an initial mode of operation that can be controlled with the power button  404 . Additional presses of the power button  404 , in this example, cycle through selection of a left lens, a right lens, and power off. Typically, with the eyewear switched off, pressing the power button  404  initiates the eyewear with both a left and a right lens alternating between a clear state and a dark state.  FIGS. 6 and 7  illustrate the eyewear during a clear state and a dark state, respectively, in which all zones are switched. Alternatively, the zones of only one lens can be switched as illustrated in  FIGS. 8 and 9 . Difficulty level can be adjusted at any time, and a new difficulty level displayed in the display region  510 . 
     Difficulty levels may be changed by altering a duration of being in a dark state or by altering a duration of being in a clear state, or a combination of both. For example, a difficulty level may have a fixed transparent state duration of 0.1 seconds, while dark state (obscuring state) has a variable duration that increases with increasing level of difficulty. For example, the most difficult level may provide a 0.9 second interval of obscuration during which the wearer&#39;s vision is obstructed. These are examples of altering a duty cycle to change a percentage of a cycle in which a lens is in a particular state. Additionally, in this example, because a transparent state is remained constant, a frequency also changes with each level (as indicate below). However, it is also contemplated that a frequency is remained constant for a given level, which would then cause the clear state duration to change with a change in the duty cycle for the dark state. While the dark state is discussed in this example, it is contemplated that a clear state could be substituted in this example for the dark state. 
     The following is a table showing a relationship between duty cycle, frequency, and level when one of the spectral transmittance states is remained constant for a repetitive sequence of clear state/dark state intervals. 
     
       
         
           
               
               
               
               
               
             
               
                   
                   
               
               
                   
                   
                 Dark State 
                 Duty Cycle 
                 Frequency 
               
               
                   
                 Level 
                 (Sec.) 
                 (%) 
                 (Hz) 
               
               
                   
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                 1 (easiest) 
                 0.025 
                 20 
                 8 
               
               
                   
                 2 
                 0.043 
                 30 
                 7 
               
               
                   
                 3 
                 0.067 
                 40 
                 6 
               
               
                   
                 4 
                 0.1 
                 50 
                 5 
               
               
                   
                 5 
                 0.15 
                 60 
                 4 
               
               
                   
                 6 
                 0.233 
                 70 
                 3 
               
               
                   
                 7 
                 0.4 
                 80 
                 2 
               
               
                   
                 8 (hardest) 
                 0.9 
                 90 
                 1 
               
               
                   
                   
               
            
           
         
       
     
       FIG. 19  illustrates a clear (e.g., less attenuated) state and dark (e.g., more attenuated) state duration corresponding to the above-provided table, in accordance with embodiments of the present invention. The representative arrangement of eight levels of difficulty represented by  FIG. 19  include durations of clear state intervals and dark state intervals for an “easiest” level  1902 , a “hardest” level  1916 , and intermediate levels  1904 ,  1906 ,  1908 ,  1910 , and  1912  are shown. In the example levels of  FIG. 19 , clear state intervals  1918 ,  1920 ,  1922 ,  1924 ,  1928 ,  1930 , and  1932  have a fixed duration of 0.1 sec, while dark state intervals  1919 ,  1921 ,  1923 ,  1925 ,  1927 ,  1929 ,  1931 , and  1933  have durations that increase with increasing level of difficulty. For example, the most difficult level  1916  provides a 0.9 sec interval of obscuration during which the wearer&#39;s vision is obstructed. For all the levels of  FIG. 19 , a repetitive sequence of clear state/dark state intervals are provided and clear state/dark state intervals for a representative 1 second time period are shown. As previously discussed with the above table, maintaining a constant duration for a single state may cause both a frequency and a duty cycle to change when also changing a duration for a second state of spectral transmittance. 
     As previously indicated, the clear state may be substituted for a dark state to result in the following table identifying an exemplary sequence of light state/dark state repetitive cycles having a constant dark state of 0.01 seconds. 
     
       
         
           
               
               
               
               
               
             
               
                   
                   
               
               
                   
                   
                 Light State 
                 Duty Cycle 
                 Frequency 
               
               
                   
                 Level 
                 (Sec.) 
                 (%) 
                 (Hz) 
               
               
                   
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                 1 (easiest) 
                 0.025 
                 20 
                 8 
               
               
                   
                 2 
                 0.043 
                 30 
                 7 
               
               
                   
                 3 
                 0.067 
                 40 
                 6 
               
               
                   
                 4 
                 0.1 
                 50 
                 5 
               
               
                   
                 5 
                 0.15 
                 60 
                 4 
               
               
                   
                 6 
                 0.233 
                 70 
                 3 
               
               
                   
                 7 
                 0.4 
                 80 
                 2 
               
               
                   
                 8 (hardest) 
                 0.9 
                 90 
                 1 
               
               
                   
                   
               
            
           
         
       
     
       FIG. 20  illustrates a clear (e.g., less attenuated) state and dark (e.g., more attenuated) state duration corresponding to the above-provided table, in accordance with embodiments of the present invention. The representative arrangement of eight levels of difficulty represented by  FIG. 20  are the inverse of those discussed with respect to  FIG. 19 . The levels illustrated in  FIG. 20  include durations of clear state intervals and dark state intervals for a “hardest” level  2002 , an “easiest” level  2016 , and intermediate levels  2004 ,  2006 ,  2008 ,  2010 , and  2012  are shown. In the example levels of  FIG. 20 , dark state intervals  2018 ,  2020 ,  2022 ,  2024 ,  2028 ,  2030 , and  2032  have a fixed duration of 0.1 sec, while clear state intervals  2019 ,  2021 ,  2023 ,  2025 ,  2027 ,  2029 ,  2031 , and  2033  have durations that increase with decreasing level of difficulty. For example, the least difficult level  2016  provides a 0.9 sec interval of less attenuating spectral transmittance. For all the levels of  FIG. 20 , a repetitive sequence of clear state/dark state intervals are provided and clear state/dark state intervals for a representative 1 second time period are shown. 
     Additional arrangements are contemplated for affecting a perceived level of difficulty by a wearer of vision training eyewear. For example, the duration of a dark state and the duration of a light state may be altered in combination or independently. For example, a one-to-one ratio may be maintained between a dark state and a light state while changing the duration used for the one-to-one ratio (e.g., 75 millisecond dark state and a 75 millisecond light state), which essentially changes a frequency (as will be exemplified below). Additionally, it is contemplated that a dark state maintains a fixed duration while the light state duration is altered to affect a perceived level of difficulty (as discussed above). Further, any combination of (1) fixed duration light state/variable duration dark state, (2) fixed duration light state/fixed duration dark state, and (3) variable duration light state/fixed duration dark state may be implemented in an exemplary embodiment of the present invention. 
     Further, it is contemplated that a light state and a dark state may maintain a common duty cycle (e.g., 50% dark-50% light, 40% dark-60% light, 60% dark-40% light) but the frequency may be adjusted. For example, the following table utilizes an exemplary 50% duty cycle for a 1 second period the dark state and the light state repetitive cycle. Therefore, a level of difficulty is adjusted by altering a frequency at which the cycle occurs. The following is an example and it is contemplated that other frequencies, duty cycles, and durations may be used. 
     
       
         
           
               
               
               
               
               
             
               
                   
                   
               
               
                   
                   
                 Dark State 
                 Duty Cycle 
                 Frequency 
               
               
                   
                 Level 
                 (Sec.) 
                 (%) 
                 (Hz) 
               
               
                   
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                 1 (easiest) 
                 0.5 
                 50 
                 16 
               
               
                   
                 2 
                 0.5 
                 50 
                 14 
               
               
                   
                 3 
                 0.5 
                 50 
                 12 
               
               
                   
                 4 
                 0.5 
                 50 
                 10 
               
               
                   
                 5 
                 0.5 
                 50 
                 8 
               
               
                   
                 6 
                 0.5 
                 50 
                 6 
               
               
                   
                 7 
                 0.5 
                 50 
                 4 
               
               
                   
                 8 (hardest) 
                 0.5 
                 50 
                 2 
               
               
                   
                   
               
            
           
         
       
     
       FIG. 21  illustrates a clear (e.g., less attenuated) state having a fixed duty cycle and a dark (e.g., more attenuated) state having a fixed duty cycle corresponding to the above-provided table, in accordance with embodiments of the present invention. The representative arrangement of eight levels of difficulty represented by  FIG. 21  include durations of clear state intervals and dark state intervals for an first level  2102 , an eighth level  2116 , and intermediate levels  2104 ,  2106 ,  2108 ,  2110 , and  2112  are shown. In the example levels of  FIG. 21 , clear state intervals  2118 ,  2120 ,  2122 ,  2124 ,  2128 ,  2130 , and  2132  have a contestant duty cycle, but their durations change with a change in frequency. Similarly, the dark state intervals  2119 ,  2121 ,  2123 ,  2125 ,  2127 ,  2129 ,  2131 , and  2133  have durations that increase with decreases in frequency, while maintaining a constant duty cycle. For all the levels of  FIG. 21 , a repetitive sequence of clear state/dark state intervals are provided and clear state/dark state intervals for a representative 1 second time period are shown. 
     Additionally, it is contemplated that a frequency may be maintained constant (e.g., 2 Hz, 5 Hz, 8 Hz, 12 Hz, 20 Hz) while adjusting the duty cycle for one of the spectral transmittance states (i.e., dark state, light state, or mid-level state). The following table provides an exemplary aspect where a 10 Hz frequency (exemplary in nature) is maintained while adjusting a duty cycle for the dark state. As previously indicated, this is but one exemplary arrangement of frequency, duty cycle, and/or duration that may be adjusted. Additional aspects are contemplated. 
     
       
         
           
               
               
               
               
               
             
               
                   
                   
               
               
                   
                   
                 Dark State 
                 Duty Cycle 
                 Frequency 
               
               
                   
                 Level 
                 (Sec.) 
                 (%) 
                 (Hz) 
               
               
                   
                   
               
             
            
               
                   
                 1 (easiest) 
                 0.02 
                 20 
                 10 
               
               
                   
                 2 
                 0.03 
                 30 
                 10 
               
               
                   
                 3 
                 0.04 
                 40 
                 10 
               
               
                   
                 4 
                 0.05 
                 50 
                 10 
               
               
                   
                 5 
                 0.06 
                 60 
                 10 
               
               
                   
                 6 
                 0.07 
                 70 
                 10 
               
               
                   
                 7 
                 0.08 
                 80 
                 10 
               
               
                   
                 8 (hardest) 
                 0.09 
                 90 
                 10 
               
               
                   
                   
               
            
           
         
       
     
       FIG. 22  illustrates a clear (e.g., less attenuated) state and dark (e.g., more attenuated) state duration corresponding to the above-provided table, in accordance with embodiments of the present invention. The representative arrangement of eight levels of difficulty represented by  FIG. 22  include durations of clear state intervals and dark state intervals that maintain a constant frequency, but adjust a duty cycle to change a level of difficulty. For example, the level of  FIG. 22  include an “easiest” level  2202 , a “hardest” level  2216 , and intermediate levels  2204 ,  2206 ,  2208 ,  2210 , and  2212  are shown. In the example levels of  FIG. 22 , a constant frequency of 10 Hz is represented (10 cycles per second) with a changing duty cycle for the dark state (and as a result, the clear state). Consequently, the clear state intervals  2218 ,  2220 ,  2222 ,  2224 ,  2228 ,  2230 , and  2232  have a duration that decreases with an increase in the dark state duty cycle. The dark state intervals  2219 ,  2221 ,  2223 ,  2225 ,  2227 ,  2229 ,  2231 , and  2233  have durations that increase with increases in the dark state duty cycle. For all of the levels of  FIG. 22 , a repetitive sequence of clear state/dark state intervals are provided and clear state/dark state intervals for a representative 1 second time period are shown. 
     These arrangements of clear state/dark state intervals are examples, and other arrangements can be used, including those in which both clear state and dark state interval durations are varied, or a frequency at which clear state/dark state intervals are switched. At frequencies greater than about 10-20 Hz, alternating clear and dark levels tend to merge and can be perceived as gray. This merger occurs at different frequencies for central vision and peripheral vision, and peripheral vision tends to note flicker at higher frequencies. Durations of dark/light intervals can be selected based on such merger. Visual challenges can be more noticeable at rates at which flicker is observed, or at lower rates. It is understood that in certain embodiment, the merger of the clear and dark may be desirable, such as when viewing a video display presenting three-dimensional imagery, to be discussed in more detail hereinafter. 
     Levels of difficulty can also be associated with the pattern or sequence of zones that are controlled to be in a clear state or a dark state, and level adjustment is not limited to clear state/dark state interval durations. Level adjust buttons can be configured to alter obscuration patterns, sequences, and/or timings to select visual challenges. 
     In another example illustrated in  FIG. 10 , a temple piece  1000  is provided with a power switch  1002 , a row selection switch  1004 , and a column selection switch  1006 . Repeated actuations of the switches  1004 ,  1006  permitting selection of different rows or columns of zones, respectively. Zone timing can be altered with repeat actuations of the power switch  1002 . 
     In yet another example, it is contemplated that a user may activate one or more inputs (e.g., switches, buttons, controls) to change a desired duty cycle for a particular state (i.e., dark state, light state, mid-level state). Similarly, a user may activate one or more inputs to change a desired frequency for a particular state. Further yet, it is contemplated that a third party may activate an input (e.g., wireless input device) to change the duty cycle and/or frequency experienced by a user. Therefore, the processors, memory, controls, and other components discussed herein may be adapted to receive, process, and transform a desired frequency and/or duty cycle input from a person. An input for a desired duty cycle and/or frequency may be by way of a selected “level” that incorporates a particular duty cycle and/or frequency, or the input may be for a particular duty cycle and/or a particular frequency. 
     The low power lens may have any amount of minus power, up to that for a concentric lens for a given base curvature. Low power lenses may, for example, have more minus power than −0.005 diopter, for example more than −0.01 or −0.02 diopter and particularly in the range of −0.01 to −0.12 diopter, for example −0.04 to −0.09 diopter. Such low power lenses achieve a number of advantages. The low power lenses have less taper, and can be thinner than zero power lenses. The reduction in taper produces a corresponding reduction in peripheral prism that would otherwise be induced by the excessively non-parallel surfaces of the plano lenses. Thinner lenses also provide better physical stability, improved optical quality, lower weight, and more uniform light transmission than plano lenses. A physiologic advantage of the low minus lens is that it better matches the accommodative posture of athletes and other persons engaged in highly visually demanding and/or stressful activities. 
     Patterns or sequences for a left eye and a right eye can be activated at different frequencies, amplitudes (different light transmissions), duty cycles (different relative on/off durations), and phases. Patterns need not be switched at a constant frequency but can be at chirped or other variable frequencies or can be switched at random intervals. While lens transmittance is varied in some examples, a transmitted light state of polarization can be varied as well. Such polarization modulation can be conveniently provided with zones defined by nematic liquid crystals. The lenses can also be tinted or neutral gray to statically control light transmission, or photochromic substrates can be used. 
     Eyewear and eyewear systems are conveniently configured to present predetermined patterns and pattern sequences at fixed or variable rates. Typically, a user or trainer can select additional patterns, pattern sequences, obscuration extents, variable or fixed pattern rates, pattern colors or color sequences, or other vision obscurations. These additional training selections can be selected using a personal computer or other computer system that is configured to present a range of customization options for selection based by the user or trainer using a keyboard or pointing device such as a mouse. After these additional training sequences are designed, the sequences can be stored in a memory and communicated to the eyewear system for storage at an eyewear controller that may or may not be integral with the eyewear. Customization and pattern selection can be based on sport-specific functions, specific training goals, wearer physiology (eye separation, orbit asymmetry) or otherwise configured. 
     In other examples, vision training apparatus such as single lens or dual lens eyewear (for example, eyeglasses or goggles), protective shields (for example, hockey face shields), or fixed apparatus (for example, a stationary viewing or protective screen) can be configured to present obscurations based on moiré patterns. Moiré patterns are generally considered to be interference patterns that are formed by the superposition of two or more repetitive patterns such as grid patterns or other periodic or aperiodic patterns such as the alternating transparent and opaque strips provided by Ronchi rulings. One or more electrically switchable pattern layers can be defined so that pattern regions are selectable to present moiré patterns in the user&#39;s visual field. For example, a lens can include a first pattern layer and a second pattern layer, wherein the first and second layers are offset with respect to each other. Pattern segments of one or both of the pattern layers can be selected to provide obscurations that include a moiré pattern. For example, the first pattern layer and the second pattern layer can be based on the same pattern. One of the pattern layers can be selectively switched to produce obscuration patterns in which various combinations of the pattern segments in the first pattern layer are activated. Moiré patterns can be produced by selectively switching pattern segments in both the first pattern layer and the second pattern layer. In this way, both moiré and other patterns can be provided. In some examples, one of the pattern layers can be configured so that substantially all pattern segments are normally activatable together, but are not individually selectable. 
     While patterns can be provided based on interference of two or more patterns established by two active pattern layers, in other examples, an active pattern layer (i.e., a pattern layer in which at least some pattern segments have transmittances or other optical properties that can be selectively switched) can be combined with a fixed pattern layer. Moiré patterns can then be presented based on selective activations of pattern segments in the active pattern layer in combination with the fixed pattern layer. Moiré patterns can also be provided with a switchable viewing screen in combination with a fixed pattern. In some training situations, two fixed patterns can be used, and a moiré pattern selected based on a relative angular or linear displacement of the fixed patterns. Eyewear systems can provide electrically switchable eyewear and a separate fixed pattern layer that can have a user selectable angular displacement about a visual line of sight or linear displacement perpendicular to the visual line of sight. For convenience, both such displacements are referred to herein as displacements with respect to a line of sight. 
     Curved Eyewear 
     Turning to  FIG. 11 , illustrates an exemplary curved eyewear  1100  in accordance with embodiments of the present invention. The curved eyewear  1100 , as seen from a frontal perspective, includes a superior member  1102  and an inferior member  1104  that both comprise a portion of a frame. The frame is effective for maintaining a lens having two portions  1106  and  1108  in a curved orientation. 
     As discussed herein, a lens may include a substrate, one or more coating materials, or components, all of which work together to allow transmission of light or obscure the transmission of light as perceived by a wearer of the curved glasses. Additionally, as used herein, a lens may constitute a single portion effective for controlling light transmission perceived by a single eye. Further yet, as used herein, a lens may constitute a common member having two portions, where each portion of the common member is effective for controlling light transmission perceived by a unique eye of a wearer. 
     Returning to  FIG. 11 , the portion  1106  may, in an exemplary embodiment, be a separate member from the portion  1108 . However, in an additional exemplary embodiment, the portion  1106  and the portion  1108  are a common member, but serving different portion of a wearer&#39;s visual spectrum (e.g., a common lens serving two different eyes). 
     In an exemplary embodiment, the superior member  1102  forces the portion  1106  to have a defined curve. For example, the portion  1106  may naturally be a flat substrate that lacks an appreciable curve. However, the superior member  1102  may guide the portion  1106  into a curved orientation and maintain the portion  1106  in that curved orientation. As will be discussed in detail hereinafter, the superior member  1102  may include a channel (not shown) that is adapted to receive a superior edge of the portion  1106 . The channel may have a curve that is similar to or approximately the same as a desired curved orientation of the portion  1106  (or a lens in general). 
     Additionally, it is contemplated that a channel within the superior member  1102  is slightly smaller in diameter than the desired curve of a received lens, but the width of the curved channel is wider than the width of the received lens that is to be maintained within the channel. Further yet, it is contemplated that a channel within the superior member  1102  is slightly greater in diameter than the desired curved of a received lens, but with a width of the curved channel that varies with respect to the location in the curve. Both of these examples are contemplated in an effort to provide a receiving channel in which a lens having electrically variable spectral transmittance may be maintained in a curved orientation while not interfering with the ability of the lens to consistently, across a whole surface, vary light transmittance. As will be discussed in more detail below, adjusting the curve of a channel and the width of the channel prevents pinch points, which disrupt the electrically variable spectral transmittance of a lens near a pinch point. 
       FIG. 12  illustrates an exemplary curved eyewear  1200  from an exploded posterior perspective in accordance with embodiments of the present invention. The curved eyewear  1200  is comprised of a superior member  1202 , an inferior member  1204 , a left lens portion  1206 , a right lens portion  1208 , a superior channel  1210 , an inferior channel  1212 , a power source  1214 , a programmable control board (PCB)  1216 , and maintaining member receiving slots  1218 . 
     The superior member  1202  may be constructed from a shatter resistant polymer capable of withstanding an impact. For example, when the curved eyewear  1200  is used in an athletic activity (or any activity) that presents a possibility of an object (e.g., ball) contacting the curved eyewear  1200 , the ability of the materials to resist breaking is beneficial for both the wearer&#39;s safety and the longevity of the curved eyewear  1200 . Consequently, the right lens portion  1208  and the left lens portion  1206  may also be constructed from a shatter-resistant material, such as a polymer or other similarly characterized material. 
     In an exemplary embodiment, a curved lens is not made with glass. As will be appreciated, glass may shatter upon impact and potentially cause damage to a wearer&#39;s vision. Therefore, in an exemplary embodiment of the present invention, a curved lens is not made from glass, but instead from a plastic material having characteristics (e.g., transparency) suitable for use as a lens. Further yet, in an exemplary embodiment, the lens is constructed from a malleable plastic material that is bendable and therefore able to be curved at ambient temperatures and with reasonable pressure. For example, a lens is constructed, in an exemplary embodiment, from a flat plastic substrate (i.e., physical material onto which electrically variable transmittance materials may be adhered) that, at room temperature, may be curved to form a curved lens. The plastic substrate in this example is then maintained in a curved orientation (e.g., position) by a typical force that may be exerted by a typical eyewear frame. However, it is contemplated that a lens may also be constructed of glass in an exemplary embodiment. 
     The curved eyewear  1200  is depicted having two distinctly separate lens portions, the right lens portion  1208  and the left lens portion  1206 . However, as previously discussed, it is contemplated that a single lens may be utilized in embodiments of the present invention, as depicted in  FIG. 15  hereinafter. A lens portion, regardless if it is a single or part of a pair of lenses, may have a number of zones, as previously discussed and depicted with  FIGS. 5-9 . Therefore, in an example where a single lens serves both eyes of a wearer, because multiple zones may be included, light perceived by each of a wearer&#39;s eyes may be in phase or out of phase, or another combination of zone configurations with each other. 
     The superior member  1202  is a portion of a frame that maintains the left lens portion  1206  and the right lens portion  1208  in a position relative to a wearer&#39;s face and eyes. As is typical of an eyewear frame, the superior member  1202  is effective for maintaining the curved eyewear in a desired location relative to a wearer of the curved eyewear  1200 . The curved eyewear  1200  incorporates both the superior member  1202  and the inferior member  1204 , in combination, to maintain the left lens portion  1206  and the right lens portion  1208 . However, in an exemplary embodiment, it is contemplated that a superior member, an inferior member, or neither (e.g., rimless) may be implemented with a curved lens(es). 
     The superior member  1202  includes the superior channel  1210 . The superior channel  1210  is a recessed portion within the superior member  1202  that is adapted for receiving and maintaining an edge portion of a lens. As previously discussed, the width of the superior channel  1210  may coordinate with the width of an edge that will be received and maintained therein. Or, in an exemplary embodiment, the width of the channel  1210  is wider, at least along one or more sections, than the width of a lens that is to be maintained therein. The depth of the superior channel  1202 , in an exemplary embodiment, is sufficiently deep to maintain a lens, while minimizing an amount of the lens that is recessed within the superior channel  1210 . The superior channel  1210 , in an exemplary embodiment, also provides a cavity in which one or more electrical leads are placed. The electrical leads may be used for controlling the electrically variable transmission state of a lens and/or for connecting the power source  1214  with the PCB  1216 . 
     Similar to the superior channel  1210 , the inferior channel  1212  is a recess in a frame member, such as the inferior member  1204 , that is functional for receiving and maintaining one or more lenses. The curved eyewear  1200  is an exemplary embodiment of the present invention in which the left lens portion  1206  and the right lens portion  1208  are maintained in a curved orientation by both the superior channel  1210  and the inferior channel  1212 . However, it is contemplated that a single channel is effective for maintaining a curved orientation for one or more lenses. 
     The PCB  1216  is a programmable computing board that includes a processor and computer readable storage media. In an exemplary embodiment, the PCB  1216  is an exemplary control system  204  as previously discussed with respect to  FIG. 2 . The PCB  1216  is functional for controlling one or more states of a lens. Examples of a state include a transparent state. A transparent state is a state of light transmission through a lens with minimal disruption by electrically variable spectral transmittance manipulation. Stated differently, an electrically variable spectral transmittance lens, when supplied power, may be in a “dark” state or a “light” state, depending on the inherent characteristics of the material relied upon to alter the spectral transmittance characteristics of the lens. A dark state is one that obscures light transmittance through the lens to a greater degree than when spectral transmittance is not reduced (e.g., power applied, power not applied). Similarly, a light state is one that does not additionally obscure light transmittance through the lens than when spectral transmittance is reduced (e.g., power applied, power not applied). Therefore, as used herein, a transparent state is a state that allows a greater percentage of spectral transmittance to occur than an obscured state. Similarly, as used herein, an obscured state is a state that allows a lesser percentage of spectral transmittance to occur than a transparent state. Consequently, a transparent state and an obscured state are relative terms to one another as used herein. 
     The PCB  1216 , in an exemplary embodiment, is adapted to synchronize an out-of-phase flicker (e.g., strobe effect) between a transparent state and an obscured state for the left lens portion  1206  and the right lens portion  1208 . The synchronization of the out-of-phase flicker is coordinated with a refresh rate of a display device. For example, a display device, such as a monitor, television, and/or a projector (and associate viewing surface), refresh a displayed image a particular number of times per unit of time. This is commonly measured in hertz, which are cycles per second. 
     In an exemplary embodiment of the present invention, curved eyewear are synchronized with a refresh rate of a display device. The synchronization allows one portion of the curved lens to be transparent while another portion of the curved lens is obscuring. The cycle from transparent to obscuring coordinates with the display device so that an image intended to be perceived by a right eye is displayed on the display device as the lens associated with the right eye of a wearer is transparent in state. Similarly, the cycle from transparent to obscure is coordinated so that when an image intended to be perceived by the left eye of a wearer is displayed on the display device, the lens associated with the left eye is transparent. Conversely, the lens associated with the eye that is not intended to perceive a given image at a particular time is obscured. 
     For example, a television that has a refresh rate of 240 Hz (240 images per second are displayed) may be synchronized with curved eyewear so that a left lens is transparent 120 times per second and obscured the other 120 times per second. Similarly, the 120 per second that the left lens is obscured, the right lens is transparent and vice versa. Therefore, the television may show 120 images per second intended for the left eye to perceive and an alternating 120 images per second intended for the right eye to perceive. This process of synchronizing two lens portions out of phase with each other and a television refresh rate allows for three-dimensional (3D) viewing experience of the content displayed by the television. 
     Advantages of curved eyewear having a curved lens when viewing 3D include allowing a wearer of the curved eyewear to utilize a greater range of peripheral vision in a 3D viewing experience. For example, when viewing a large display device from relatively close distance (e.g., front row of a movie theater) a portion of the displayed content is outside of the wearer&#39;s central vision that is served by standard flat lens 3D viewing glasses. Further, in an IMAX type viewing environment that intends to take advantage of a viewer&#39;s peripheral visions, non-wrapping 3D glasses fail to provide the necessary augmentation to the wearer&#39;s vision. Consequently, a curved lens that wraps around a wearer&#39;s field of vision provides an enhanced and complete 3D viewing experience. 
     Curved eyewear, in an exemplary embodiment, includes a receiver component (not shown). The receiver component receives a synchronization signal from a display device in order to synchronize the out-of-phase cycle of two lens portions of the curved eyewear with the refresh rate of the display device. For example, an infrared receiver that receives an infrared signal from the display device or an associated content source. Additional examples of a receiver component include a radio frequency (“RF”) receiver. For example, BLUETOOTH (IEEE Standard 802.15), is a short range RF specification that is contemplated as being utilized in embodiment of the present invention. 
     In addition to aiding in the synchronization of curved eyewear and a display device, the receiving module may also (or in the alternative) function to receive one or more remote control signals to control the curved eyewear. For example, functionality that is adjustable directly from the curved eyewear may also be adjusted remotely. For example, the flicker rate of the electrically adjustable spectral transmittance of a curved lens may be adjusted (e.g., frequency, duration, intensity, on/off) by a remote control that communicates with the curved eyewear by way of the receiving module. 
     For example, an athletic trainer may adjust the intensity level (e.g., change a duration of obscured state or transparent state of one or more lens portions) using a remote control while an athlete is training with the curved eyewear. Consequently, the athlete may be running a receiving route with the curved eyewear at an easy intensity level, and after the athlete initially identifies an incoming ball, the trainer may increase the intensity level of the curved eyewear to enhance the training experience. 
     The receiving module, in an exemplary embodiment, is coupled, either directly or indirectly, to the PCB  1216 . As a result, processing of received signals may be accomplished in whole or in part by one of the receiving module or the PCB  1216 . 
     Returning to  FIG. 12 , the superior member  1202  may have two maintaining member receiving slots  1218 . The maintaining member receiving slots  1218  are functional for receiving a maintaining member, such as a strap. For example, when the curved eyewear  1200  is used in an athletic or moving activity, a strap allows the curved eyewear to be maintained in a desired position relative to the face of a wearer. In an additional exemplary embodiment, the maintaining member received at the maintaining member receiving slots  1218  includes a temple, such as the temple piece  302  previously illustrated with respect to  FIG. 3 . 
       FIG. 13  depicts a portion of a curved eyewear frame  1300  having a curved channel  1302  in accordance with an embodiment of the present invention. As previously discussed, a channel for receiving and maintaining a curved lens within a curved eyewear may not have the same curve diameter as the frame. For example, in an embodiment, in order to increase an amount of “wrap,” which is an amount of extension around a wearer&#39;s head away from a medial line, the frame may have a smaller diameter curve than a curved lens associated with the frame. In this example, in an effort to reduce the amount of strain placed on a curved lens while maximizing an amount of wrap provided by the curved eyewear as a whole, the curved lens diameter is get greater than the curved frame diameter. An analogy of this concept for illustration purposes comes from a race driver&#39;s path when taking a corner on a race track. In this analogy, the driver reduces the amount of turning within a corner by starting on the outside of the corner cutting to the inside of the corner near the apex and exiting the corner toward the outside edge of the track. 
     The curved channel  1302  follows the analogy provided above such that the diameter of the curved channel  1302  is greater than the general diameter of the frame  1300 . For example, the distance between the “inside” edge of the frame  1300  and the curved channel  1302  changes from a first distance  1304 , to a smaller distance  1306  near the apex of the curve. Finally, the distance between the inside edge of the frame  1300  and the curved channel  1302  increases from the distance  1306  to a distance  1308  at the “exit” of the curve. Therefore, a desired amount of peripheral field of vision for a wearer of the curved eyewear is achieved while reducing the curve of the actual lens within the curved eyewear. It is understood that in an exemplary embodiment, the diameter of a curved lens may be similar to that of a frame in which it is maintained. Further, while  FIG. 13  illustrates a curved channel  1302  that accommodates a lens that services only one eye, a curved channel may extend along a frame to similarly accommodate a lens that services both eyes. 
       FIG. 14  depicts a front perspective view of a curved eyewear  1400  in accordance with embodiments of the present application. The curved eyewear  1400  is suitable for providing a wrap effect around a wearer&#39;s field of vision. Consequently, the curved eyewear  1400  are functional for allowing a wearer to have electrically switchable spectral transmittance that affects light perceived in peripheral fields of view. 
     Unlike typical flat lenses placed in a curved frame, eye lash contact by a wearer of the curved eyewear may be reduced. For example, when a flat lens is angled within a curved frame to provide the appearance, but not the benefits, of a curved lens and frame solution, the wearer may contact the un-curved, but angled, lens with his or her eye leash. In an effort to force a non-curved lens in a curved frame to provide peripheral field of view electrically switchable spectral transmittance, the lens is angled so a medial edge is pushed away from a wearer&#39;s face to allow a lateral edge of the lens to extend as posterior as possible in an attempt to cover a portion of the peripheral field of view. However, this angling of the lens causes the lens to come closer in proximity to the eye, and therefore eyelashes, of a wearer. When utilizing curved eyewear having electrically switchable spectral transmittance, the wearer does not desire for the distracting and interfering contact of eyelashes with the lens. Therefore, a curved lens avoids the severity of eyelash contact realized with a flat lens. 
     Returning to  FIG. 14 , a control portion  1402  for controlling functionality of the curved eyewear (e.g., electrically variable spectral transmittance) is illustrated as being maintained on a right temple of the curved eyewear  1400 . The control portion  1402 , in an exemplary embodiment, is similar to the level adjust buttons  404  and  406  previously discussed with respect to  FIG. 4 . The curved eyewear  1400  also includes a power supply  1404 . A previously discussed, the power supply  1404  may include a battery or other replaceable or rechargeable power supply. In an exemplary embodiment, the power supply  1404  is recharged through a Universal Serial Bus (USB) connection (not shown) associated with the curved eyewear  1400 . For example, in addition to updating computer readable instructions for a PCB of the curved eyewear  1400 , a USB connection may also be utilized to charge the power supply  1404 . 
       FIG. 15  depicts a curved lens  1500  effective for manipulating perceived light by two eyes of a human wearer in accordance with an embodiment of the present invention. The curved lens  1500  is a unitary substrate to which an electrically variable spectral transmitting material is coupled. For example, an LCD material may be incorporated within, thereon, or otherwise positioned relative to a polymer substrate having shatter-resistant characteristics that are better than glass. The curved lens  1500  is effective to manipulate light perceived by both a left eye and a right of a wearer. However, it is understood that, as previously discussed, one or more zones (e.g., portions) of electrically variable spectral transmittance are contemplated as being implemented on the curved lens  1500  to allow for localized manipulation of perceived light. 
       FIG. 16  depicts a top view of a curved eyewear  1600  in accordance with an embodiment of the present invention. The curved eyewear includes a curved frame  1602  and a curved lens  1604 . 
     An exemplary illustration of a field of view provided by a flat lens is limited to the exemplary central field of view  1606 . However, by providing the curve lens  1604  that wraps around a wearer, the field of view is increased to include the peripheral field of view  1608 . Therefore, it is desirable for athletic vision training and 3D applications to increase a field of view to include the peripheral field of view  1608  in addition to the central field of view  1606 . 
       FIG. 17  depicts an exemplary curved lens  1700  in accordance with embodiment of the present invention. A curve  1702  is depicted along the general curve of the lens  1700 . The curve  1702  has a diameter (Ø)  1704 . The diameter  1704  of the curve  1702  defines a curved orientation of the curved lens  1700 , where the curved orientation of the lens  1700  has a diameter of  1704 . However, as is illustrated at positions  1706 - 1712 , the curved lens  1700  does not adhere to a perfect circle defined by the curve  1702 , but instead, the curved orientation of the curved lens  1700  is defined as a whole by the curve  1702 . 
     For example, the curved lens  1700  actually intersects the illustrated curve  1702  at points  1706  (a left temple region),  1708  (a bridge region), and  1710  (a right temple region). However, the curved lens  1700  diverges, for example, at point  1712  from the curve  1702 . The divergence of the curved lens  1700  is sometime referred to herein as an approximate curve as it is not consistently defined by a particular diameter, but instead as a whole is defined by a diameter. As previously discussed, the curvature of the curved lens  1700  may diverge to provide additional clearance from a wearer&#39;s eyelashes and/or to reduce stress on the curved lens  1706  to minimize negative effects to the electrically switchable characteristics of the curved lens  1700 . 
     The diameter  1704  is between 120 millimeters and 200 millimeters in an exemplary embodiment. It is contemplated that the diameter is greater than or less than this range in other embodiments. In yet other embodiments, the diameter  1704  is 130 millimeters to 180 millimeters. An exemplary embodiment includes a curved lens with a curved orientation approximately defined by a curve having a diameter of 175 millimeters, which may also be expressed as 11.42 diopters. In yet another exemplary embodiment, as will be discussed in more detail hereinafter, a curved orientation may be defined by a curve having a diameter between 130 and 140 millimeters. For example, a curved lens, in an exemplary embodiment, has a curved orientation defined by an approximate curve having a diameter of 135 millimeters, which may also be expressed as 14.81 diopters. 
       FIG. 18  depicts an exemplary curved lens  1800  in accordance with an embodiment of the present invention. The curved lens  1800  includes a left portion  1802 , a right portion  1804  and a bridge portion  1814 . A previously discussed with respect to  FIG. 17 , a curved lens may be defined, in part, by an approximate curve; however, in an exemplary embodiment, the curved lens  1800  is defined by a curve of a particular portion (e.g., left portion  1802 , right portion  1804 ). Consequently, a curve  1806  is depicted along the general curve of the left portion  1802 . The curve  1806  has a diameter (Ø 1 )  1810 . The diameter  1810  of the curve  1806 , in an embodiment, defines a curved orientation of the curved lens  1800  as a whole, where a portion of the curved orientation of the curved lens  1800  has a diameter of  1810 . Similarly, a curve  1808  is depicted along the general curve of the right portion  1804 . The curve  1808  has a diameter (Ø 2 )  1812 . The diameter  1812  of the curve  1808 , in an embodiment, also may define a curved orientation of the curved lens  1800  as a whole, where a portion of the curved orientation of the curved lens  1800  has a diameter of  1812 . 
     The bridge portion  1814  may have less of a curved orientation (i.e., a greater diameter curve defining the curved orientation) than the left portion  1802  and the right portion  1804 . Therefore, defining the curved orientation of the curved lens  1800 , as a whole, is done by utilizing a diameter of a portion of the curved lens  1800 . In this example, the curved lens  1800  is defined by a first curve (curve  1806 ) and/or a second curve (curve  1808 ) having respective diameters Ø 1    1810  and Ø 2    1812 . In an exemplary embodiment, the diameters Ø 1    1810  and Ø 2    1812  are between 130 and 140 millimeters. 
     Many different arrangements of the various components depicted, as well as components not shown, are possible without departing from the spirit and scope of the present invention. Embodiments of the present invention have been described with the intent to be illustrative rather than restrictive. Alternative embodiments will become apparent to those skilled in the art that do not depart from its scope. A skilled artisan may develop alternative means of implementing the aforementioned improvements without departing from the scope of the present invention. 
     In view of the many possible embodiments to which the principles of the disclosed technology may be applied, it should be recognized that the illustrated embodiments are only preferred examples and should not be taken as limiting the scope of the technology. Rather, the scope is defined by the following claims. We therefore claim all that comes within the scope and spirit of the appended claims.