Patent Abstract:
a therapeutic eye and eyelid cover provides heated saturated air to the covered tissue and a transparent front to enable clear vision during use . the cover includes heating means and means for saturating the air enclosed against the face with water vapor , preventing evaporation from the eye and eye lids and enhancing heat transfer to the covered tissue . the transparent front is constructed to prevent condensation and maintain clear vision at all times during use .

Detailed Description:
the device shown in fig1 and 2 of the drawings comprises a pair of goggles including two ocular units 10 and an adjustable frame 11 that allows both the distance between the ocular units 10 and the angle at which they sit on the face to be adjusted . the goggles are secured to the head using an adjustable elastic strap 12 . the central part of the strap 12 passes over the user &# 39 ; s head and has a power and control cable 13 attached to it . the cable 13 plugs into a power and control unit 14 that either sits on a table or ( as shown ) is attached to a belt around the user &# 39 ; s waist . this power control unit 14 contains a rechargeable battery , an on / off switch and temperature adjustment controls . the temperature and other performance data are displayed on a small liquid crystal display ( not shown ) on the housing of the power control unit 14 . a socket 15 is provided for a battery charger to be plugged into the power control unit 14 . a small variable speed and variable stroke diaphragm pump ( not shown ) in the power control unit 14 is connected to the goggles by a small diameter flexible hose 16 . each ocular unit 10 includes two lenses 18 and 19 and a heating effect is provided by an electrical heating element 17 ( fig2 ), which is located in a space between the two lenses 18 and 19 of each ocular unit 10 . this heats the air in this space , thereby warming the inner lens 18 . the heating element 17 has a cover 20 having a matt black coating and providing some radiant heat to warm the central area of the inner lens 18 . these two effects combine to ensure that the temperature of the inner lens 18 stays above the saturated air temperature inside the goggles &# 39 ; eye space . this prevents condensation and maintains a clear visual axis . the inner lens 18 of each ocular unit 10 is mounted on a main body 21 and this is surrounded by an aluminum thermal backing ring 23 that extends up to the outer lens 19 . a water reservoir 22 is contained within the main body 21 and is positioned adjacent the inner side of the inner lens 18 . the reservoir 22 is filled with an absorbent medium . the arrangement is such that , as the goggles warm up on starting , the plastic of the main body 21 , which has a much higher coefficient of thermal expansion , expands and tightens up on the aluminum thermal backing ring 23 , thereby providing enhanced heat transfer through to the main body 21 and the water reservoir 22 . the backing ring 23 is of high thermal conductivity and carries much of the heat from the heating element 17 away into the body of the goggles and the water reservoir 22 . the main body 21 of the goggles is of comparatively low heat capacity and hence allows the goggles to warm up quickly . once the temperature of the main body 21 exceeds the surface temperature of the eye and the surrounding tissue , it is the tissue that tends to condense much of the vapor and hence absorbs the latent heat that it contains . any excess liquid that might condense on the tissue surrounding the eye or the body of the goggles will tend to drain back to the absorbent - medium - filled reservoir 22 where it is available for reuse . to prevent excess radiant heat affecting the eye and the surrounding tissue , the heating element 17 is behind the inner lens 18 and is shielded by the main body 21 and the water reservoir 22 of the goggles , thereby preventing a direct line of sight with the eye . the inner lens 18 is prevented from becoming too hot by being in contact with the water in the water reservoir 22 . variation in the pressure , or “ pulsing ” of the pressure , in the ocular space , i . e . the space between the inner lens 18 of each ocular unit 10 and the associated eye and surrounding tissue , can be achieved by supplying or removing air from the ocular space through a circular manifold 24 and its associated hose connection 28 . there is a cavity within the main body 21 of each ocular unit 10 and this contains a microprocessor 26 , which transmits data corresponding to the temperature at this location . the data from both ocular units 10 is used to control the electrical supply and hence the quantity of heat generated by the heating element 17 . in this way , the temperature of the ocular environment is controlled . there is a rubber sealing ring 27 located between the inner lens 18 of each ocular unit 10 and the associated main body 21 , and the sealing ring 27 allows for any differential expansion of the main body 21 and the inner lens 18 while maintaining a watertight seal . a rubber ring 25 is fitted over the inner portion of the main body 21 of each ocular unit 10 , and the cushion effect afforded by the rubber rings 25 allows the goggles to sit comfortably on the face . as an alternative to providing the pressure modulating function via the manifold 24 and its associated hose connection , this function can be achieved by changing the pressure in the space 29 within each of the sealing rings 25 that lie in contact with the face of the user . the medium - filled water reservoir 22 can be removable for cleaning purposes and the entire goggles ( excluding the control / power unit and the electrical supply / charger unit ) can be placed in a heated environment at up to 120 ° c . to ensure microbial cleanliness . the reservoir 22 can serve as a means for adding therapeutic agents to the ocular space as a liquid instead of or combined with the water used to increase the humidity . the therapeutic agent may alternatively be a solid incorporated into a replaceable component within the device or as a vapor supplied to the device . the principal material of construction is a lightweight engineering plastics material ensuring that the weight of the goggles is modest enhancing the comfort of the user . the goggles can include refractive components within the structure of the cover or may be fitted with a mechanism ( such as slots , clips or the like ) to allow for the attachment of optical lenses or spectacles to correct the refractive error of any individual user and allow clear vision . the embodiment shown in fig3 includes left and right hand ocular units 30 that fit comfortably on the face of the user and are held vertically in a support frame 31 by pins 32 . a good seal is obtained around each of the eye cavities of the user by the use of soft rubber seals 33 and by the action of an elasticized strap 34 that pulls the goggles against the face of the user . the strap 34 also supports a battery and control unit 35 that sits at the back of the head of the user . the unit 35 contains rechargeable batteries and there is a knob 36 on the top of the unit 35 that can be rotated to operate an on - off switch and to control the level of power supplied from the unit 35 to the two ocular units 30 . the batteries within the unit 35 can be recharged using a standard battery charger ( not shown ) connected to a socket 37 . for clarity , the leads connecting the power unit 35 to the two ocular units 30 have not been shown in fig3 . each of the ocular units 30 of the embodiment of fig3 includes a mounting for a removable insert 38 and each insert 38 contains the required quantity of water and / or the required therapeutic agent for each use of the goggles . the inserts 38 fit snugly in their mountings , which may be in the form of rebates inside the body of the goggles . once in position , the inserts 38 are heated by an electrical heating element ( not shown ) contained within the main body 30 . the electrical heating elements are arranged to raise the temperature of the inner lens of each ocular unit slightly more quickly and to a slightly higher level than the removable inserts in a manner corresponding to that described above with reference to the embodiment shown in fig1 and 2 , to produce the “ clear view steam room effect ”, and the desired response . the inserts 38 can be designed so that they can be removed and discarded after each use of the device . the embodiment shown in fig3 will be cheaper and easier to use at home while giving many of the medical benefits of the fully controlled glasses above . the absence of the pressure control option and the consequent reduction in power consumption give a further option of locating the battery control unit in the way illustrated . each of the embodiments shown in the drawings seals against the face of the user so as to trap a volume of air in each of the spaces between the face of the user and the lens systems . the air in each space is heated and humidified whilst , at the same time , the user is allowed to see clearly through each of the lens systems . if , of course , the device is in the form of a face mask as opposed to a pair of goggles , there will be just one space between the face of the user and the mask . it is envisaged that the device of the present invention will be used intermittently . for example , it may be used two or three times a day for say five to ten minutes by some users , but more frequently and / or for longer periods by other users , depending on their individual requirements . 1 . rolando m , refojo m f , kenyon k r . tear water evaporation and eye surface diseases . ophthalmologica 1985 ; 190 : 147 - 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