Field Expansion Prism Glasses for Homonymous Hemianopia

DESCRIPTION (provided by applicant): The broad, long term objective of this proposal is to overcome optical design, ergonomical, and cosmetic obstacles that stand in the way of innovative lens designs for low vision enhancement. Specifically, we have chosen to carry forward the work on field expansion for Homonymous Hemianopia proposed by Dr. Eli Peli of the Schepens Eye Research Institute. The design, incorporating 40 diopter prisms in upper and lower segments, has the potential of helping the one million Americans afflicted with this condition annually. A novel oblique prism arrangement expanding vision further into the central field would be made possible by the new proposed design. Earlier use of temporary press-on Fresnel prisms and a few elementary, but functional handmade prototypes indicate the potential success of this concept, however, the lenses are not cosmetically acceptable and the cost of the lenses is excessive putting them beyond the reach of most who could benefit. Based on clinical studies, we intend to determine the optimal values of various parameters of these new prism segment lenses to make them suitable for mass production. This would reduce manufacturing time and cost by up to 70% and provide a safe, durable, and cosmetically acceptable lens to improve patient mobility. We will evaluate the feasibility of manufacturing the new design with these parameters. In phase 2 we envision developing a final lens design, based on results or our phase 1 feasibility testing, a simple fitting protocol, also through clinical trials, which will allow any practitioner to fit these lenses as easily as a flat top bifocal, making them widely available.