Contact Lenses for Color Vision Deficiency

Abstract

Color blindness or color vision deficiency (CVD) affects around 4.5% of the population in Europe. There have been several attempts to assist color-blind individuals using color filter glasses. Here, contact lenses are developed to assist individuals suffering from color blindness. Two dyes (Atto 488 and 565) that provide the desired absorption wavelength ranges are selected to be immobilized in soft contact lenses. The chosen dyes have absorption bands in wavelength ranges of 480–500 and 550–580 nm. Both dyes are individually immobilized in contact lenses, and over 95% of the light in the undesired ranges are blocked. The dyes do not diffuse out from lenses in artificial tears and contact lens storage solution. Performances of the developed contact lenses are compared to commercial color-blind glasses. The contact lenses are tested in color vision deficient patients using Ishihara test. Participants indicate enhancement in the visibility of the colors and their contrast in a color rich environment. The proposed contact lenses show enhanced results as compared to commercial color-blind glasses in indoors and achieved similar outcomes outdoors.