Abstract
Purpose :
Color vision deficiency (CVD) especially the Red-Green type, affects 4 - 8% of male and 0.4% of female populations. There is no cure for color deficiency. However, there are specially tinted lenses marketed to enhance the color contrast for CVD individuals. EnChroma glasses claim to enhance color perception without compromising color interpretation. The aim of this study was to test the overall transmission and wavelength filtering characteristics of EnChroma Cx-14 glasses objectively and determine if they subjectively change the color perception in normal subjects.
Methods :
Twenty-five males (aged 20 to 25 years) with normal vision were randomly recruited. Subjective responses of EnChroma, participants were tested by means of the digital version of Ishihara (ColorDx iPad app) and FM100 Hue tests with and without EnChroma glasses. A Ocean Opticsä spectrophotometer was used to measure the spectral transmission of EnChroma Cx-14 glasses. The FM100 tests error scores and time duration to complete the test were recorded, compared and correlated with the Ocean Optics spectral transmission curves.
Results :
Spectral transmission of EnChroma Cx-14 showed notching of wavelength starting from 450 nm that dipped down close to 0 from 475 nm to 500 nm, and from 560 nm to 575 nm. Peak sensitivity was not achieved for the wavelength of 420-450 nm. There was a significant (p = 0.018) increase in the mean FM100 test error scores with a shift towards a defect resembling tritanomaly (mean = 35), 95% CI [-94 to 165] with the EnChroma Cx-14 glasses. However, the correlation of time taken to complete the FM100 test with and without EnChroma was stronger (r = 0.82) only for the FM100 plates that test for confusion in the blue orthogonal axis of the CIE chromaticity diagram.
Conclusions :
EnChroma Cx-14 glasses are multi-notch filters that modify the wavelength transmission of the observer. Our results show that the EnChroma filters notch the blue region of the visible spectrum consistently and induce a tritan defect in individuals with normal color vision. Future studies are needed to investigate whether EnChroma filters improve the color discrimination in individuals with color vision deficiency.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.