At least 8 percent of men and 0.5 percent of women suffer from red-green color vision deficiency (CVD), totaling 13 million in the US and 350 million worldwide. While those with normal color vision see in excess of one million hues and shades, those with CVD see a vastly diminished range of colors.

People with CVD experience colors as more muted and washed out and some colors cause confusion or are more difficult to differentiate. Fortunately, researchers have created special patented glasses that can enhance color vision for those with the most common types of red-green color vision deficiency.

For the research in Current Biology, CVD participants wore special filter glasses or placebo glasses. Over two weeks, they kept a diary and were retested on days 2, 4, and 11 but without wearing the glasses. The researchers found that wearing the filter glasses increased responses to chromatic contrast response in individuals with red-green color blindness. In short, the glasses allowed them to see more hues.

It is unclear how long the improvement lasts without wearing the filters, but the evidence shows that the effect persists for some time.

“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,” says Alex Zbylut, one of the color blind participants in the study who got the placebo glasses first and then tried the special filter version afterward. “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.”