EnChroma


EnChroma lenses are glasses which claim to improve color vision in people who are color blind. The limited evidence is that they do not improve color vision.

Evidence

An experiment involving 25 males aged from 20 to 25 years. Two of those 25 were excluded because of a vision disease that may affect the color blindness. They tested whether the glasses helped people with particular deficiencies improve the way they see colors. The study involved ten individuals with hereditary deficiencies. The EnChroma Cx-14 filters did not significantly influence the vision of color blind subjects but, for two of them, the error score was improved.
In 2018, a study of EnChroma lenses proved that they merely helped color blind people to see the same colors in a different way since the colored filter altered the way colors appeared in their eyes.
The researchers found the effect of using EnChroma glasses is similar to glasses where the use of color filters changes the user's perception and increases the contrast among the colors, such as those used for shooting or hunting. The research showed that EnChroma glasses did not reveal any improvement in the Ishihara test and Farnsworth Munsell 100 hue test.

Technology

The lenses focus on the most common color vision deficiency which is caused by the red and green retinal cone cells that, when responding to light, coincide. To eliminate the overlapping of the wavelengths of light, there is an optical material called a 'multi-notch' filter, is capable of removing the exact wavelengths of light in the location where it overlaps, getting a simplified differentiation of colors. The glasses block specific wavelengths to create a clearer separation of different color signals so that they can be better calculated by the brain. The separation of signals allows most people with color blindness to distinguish colors, but the glasses will have little to no effect on the 20% of color blind people who have severe color impairment.

History

Donald McPherson invented EnChroma glasses by accident. He originally was trying to develop lens to protect surgeons during laser operations.