Novel System Supporting Color Vision Deficiency Consisting Colored Filters and Illumination Setup

Eye care and eyewear centers now offer glasses designed for individuals with color vision deficiencies (CVDs). The present work involves a detailed analysis of the optical properties of glasses enhancing color discrimination in individuals with red CVD known as protanopia. Eleven models of such glasses with optical filters were subjected to spectrophotometric studies to determine parameters such as luminous transmittance in the spectral range of 380–780 nm (mean values for daylight and night vision), signal light transmittance, and reduction quotients for red, yellow, green, and blue signal lights. The light sources included traditional incandescent illuminants and LEDs. Analysis of spectrophotometric results indicates that the use of the studied glasses may impair blue-green discrimination. An experiment on a human subject was conducted to evaluate the application feasibility of such glasses for the performance of tasks involving discrimination between blue and green colors. This study should be treated as a proof-of-concept or pilot investigation. A purpose-built system providing additional illumination of the observed objects with white, blue, and green light was also used. The experimental results were consistent with the findings of the spectrophotometric study. It was shown that the use of glasses enhancing color discrimination by individuals diagnosed with protanopia may prevent blue-green discrimination, which has significant implications for the performance of tasks involving color-coded information. In particular, this concerns color-based comparative applications involving gradable or absolute evaluations as to whether the colors in question are identical. It was found that the illumination of test objects with green or blue light during experiments restored blue-green discrimination ability in a human subject wearing glasses designed for individuals with red CVD.