Researchers at the UC Davis Eye Center have engineered special glasses that enhance color vision in those with red-green color deficiency, one of many types of color blindness. What was truly remarkable was that color vision was enhanced even when subjects were not wearing the glasses. This suggests that the brain may be adapting to the new color signal, offering long-term vision rehabilitation.
A newly lit world full with vibrant colors
Red-green color vision deficiency (CVD), also known as “anomalous trichromacy”, causes people to easily confuse shades of red and green. They also experience colors as more muted and washed out, rather than vibrant and saturated as most people see them.
The deficiency is actually much more common than people think. At least 8% of men and 0.5% of women suffered from red-green color vision deficiency.
Most are not even aware of their color deficiency, especially if it is on the milder side of the spectrum. For instance, I am one of those people. I had no idea I had CVD until I took a color vision test. While I should have been clearly reading a digit, all I could see was a mess of colored circles.
For such conditions, ophthalmologists will prescribe special color vision glasses to correct some of the red-green deficiency, which is due to light-sensitive cells in the retina failing to respond appropriately to variations in wavelengths of light.
However, the newly patented color-correcting glasses engineered at UC Davis are supposedly more advanced, thanks to spectral notch filters, which offer a more accurate color vision.
For their study, the researchers had CVD participants from the university campus wear special glasses or a pair of placebo glasses. Over two weeks, each participant had to keep a diary detailing how their experience has changed. In the meantime, they were re-tested on days 2, 4, and 11 without wearing their glasses.
The improvements were quite striking in the group that wore the red-green-color-correcting glasses. One of the participants’ testimonials is revealing, in this respect.
“When I wear the glasses outside, all the colors are extremely vibrant and saturated, and I can look at trees and clearly tell that each tree has a slightly different shade of green compared to the rest,” said Alex Zbylut, one of the color blind participants in the study who got the placebo glasses first and then tried the special filter version afterwards. “I had no idea how colorful the world is and feel these glasses can help color blind people better navigate color and appreciate the world.”
Not only did the glasses improve the chromatic contrast response, but these improvements persisted even when the filters were removed. This suggests that wearing color-correcting glasses provides an adaptive visual response.
The researchers hypothesize that modifications of photoreceptor signals activate a plastic post-receptoral substrate in the brain. However, this has to be formally studied.
The findings appeared in the journal Current Biology