A NEW ADJUSTABLE SPECTACLE LENS FOR PRESBYOPIA

THERE ARE 70 MILLION PRESBYOPES IN THE U.S.A. NOW, AND 30 MILLION WILL JOIN THESE RANKS BY THE YEAR 2000. SPECTACLE CORRECTION OF PRESBYOPIA CONSTITUTE A LARGE MARKET, AND NEW PRODUCTS HAVE BEEN DEVELOPED OVER THE YEARS IN AN EFFORT TO IMPROVE ON PREVIOUS SOLUTIONS. DESPITE ALL THESE PRODUCTS, MANY PRESBYOPES ARE STILL DISSATISFIED WITH THE AVAILABLE SOLUTIONS. THE PHASE I INVESTIGATION WILL DETERMINE THE FEASIBILITY OF AN INNOVATIVE DESIGN FOR A DEFORMABLE SPECTACLE LENS WITH ADJUSTABLE POWER "ACCOMMOLENS". AN ADJUSTABLE POWER LENS COULD BE USED IN A VARIETY OF APPLICATIONS. THE NEW DESIGN DIFFERS FROM PREVIOUS DEFORMABLE LENS DESIGNS IN MAINTAINING A FIXED VOLUME OF REFRACTIVE FLUID BETWEEN TWO PLATES, AT LEAST ONE OF WHICH IS ELASTIC. RATHER THAN CHANING THE VOLUME (AND THUS THE PRESSURE) OF THE REFRACTIVE FLUID, THE NEW DESIGN IS BASED ON CHANGING THE DISTANCE BETWEEN THE EDGES OF THE LENS' PLATES. THIS DISTANCE VARIATION COTROLS THE PRESSURE OF THE REFRACTIVE FLUID, SIMULTANEOUSLY WITH THE FORCING OF THE GEOMETRICAL BOUNDARY CONDITIONS REQUIRED FOR THE RESULTANT SURFACE CURVATURE AND LENS POWER. THIS DESIGN OFFERS NUMEROUS BENEFITS FOR THE APPLICATION IN SPECTACLE LENSES, INCLUDING REDUCED LENS THICKNESS, INCREASED OPTICAL PRECISION, REDUCED ENERGY DEMAND FOR CHANGES IN POWER, AND POSSIBLY MOST IMPORTANTLY, THE FEASIBILITY OF CONSTRUCTING A NON-ROUND, FASHIONABLE SHAPED LENS. IN PHASE I, A PRELIMINARY MODEL LENS WILL BE CONSTRUCTED USING ROUND PLATES AND WITH A SIMPLIFIED HARNESSING METHOD WHICH WILL ENABLE US TO DETERMINE OUR ABILITY TO APPROACH THE REQUIRED OPTICAL SPECIFICATIONS.