The long-term objectives of this project are to: 1) provide a soft bifocal contact lens that will overcome the drawbacks of current soft bifocal contact Ienses; 2) provide a soft bifocal contact lens that will have better image forming properties than that of previous soft bifocal contact lenses and give optimal vision to the wearer for viewing both distance and near objects; 3) provide a soft bifocal contact lens that is relatively inexpensive to manufacture, using air-bearing, computer controlled lathing or molding techniques; 4) expand the number of patients who are able to wear bifocal contact lenses.
The specific aims of this project are to: 1) transform the design for a newly patented rigid gas permeable bifocal contact lens into a design that is suitable for a soft contact lens; 2) produce a soft bifocal contact lens that will take advantage of the anatomical structure of the eye and lids for purposes of generating a vertical shifting or translational movement, so as to present one or another optical power to the eye at the desired time; 3) develop software and manufacturing techniques for the proposed lens construction that can be executed using air-bearing computer-controlled lathes. The major effort of this project will be directed towards programming and test manufacturing a recently developed rigid bifocal contact lens design, modified to produce an advanced soft bifocal contact lens. The proposed soft bifocal contact lens design has a distinct advantage over present lenses because of two features: 1) spherical optics for both distance and near lens power areas connected by a unique transition curve that eliminates visual image jump based on a modified form of monocentricity and 2) lens design features that provide controlled lens translation on the eye in order to place the desired lens power area in front of the entrance pupil of the wearer at the desired time.
