Study Finds Special Goggle Filters Can Help Color Blind People See Colors Better

A new study from the UC Davis Eye Center, conducted in collaboration with the INSERM Stem Cell Research Institute of France, found that special patented glasses designed with technically advanced spectral notch filters improve color vision for those with the types most common red-green color vision deficiency (“abnormal trichromacy”). In particular, the ability to identify and experience expanded color was also demonstrated when colorblind test subjects did not wear glasses.

At least eight in 100 men (8%) and one in 200 women (0.5%) suffer from red-green color vision deficiency (CVD), totaling 13 million in the US and 350 million throughout the world. While those with normal color vision see over a million shades and shades, those with CVD see a greatly diminished color gamut. People with CVD experience duller, fainter colors, and some colors cause confusion or are more difficult to differentiate. With an undergraduate and graduate student body of nearly 40,000, UC Davis has an estimated 1,700 students with red-green CVD.

The study evaluated the impact of spectral notch filters on improving color responses of observers with red-green CVD during two weeks of use. Filters (EnChroma glasses) are designed to increase the separation between color channels to help people with color blindness see colors with more intensity, clarity and distinction.

The research, published in Current Biology, caused CVD participants to wear special filter lenses or placebo lenses. For two weeks, they kept a diary and were analyzed again on days 2, 4 and 11, but without using the glasses. The researchers found that wearing filter lenses increased responses to the color contrast response in individuals with red-green color blindness. It is unclear how long the upgrade lasts without using the filters, but the evidence shows that the effect persists for some time.

“The extended use of these glasses increases the color response in those with abnormal trichromacy (red-green color vision deficiency),” said John S. Werner, distinguished professor of ophthalmology and leader in vision science at UC Davis Health . “We found that sustained use for two weeks not only led to an increased color contrast response, but more importantly, these improvements persisted when tested without the filters, demonstrating an adaptive visual response.”

Werner noted that this effect cannot be achieved with broadband filters sold as color blind aids. He and his research colleagues believe the study’s findings suggest that photoreceptor signal modifications activate a post-receptor plastic substrate in the brain that could be exploited for visual rehabilitation.

“When I wear the glasses outside, all the colors are extremely vibrant and saturated, and I can look at the trees and clearly say that each tree has a slightly different shade of green compared to the rest,” said Alex Zbylut, one of the colors. Blind study participants who received the placebo glasses first and then tried the special filter version. “I had no idea how colorful the world is and I feel that these glasses can help colorblind people better navigate color and appreciate the world.”

Other participants’ reactions to their experiences with glasses can be found in the Supplement section of Current biology Article.