Published November 06, 2012
For people who are colorblind, life involves little workarounds and big compromises alike.
Daily challenges range from not knowing whether meat is fully cooked to not being able to read whether a horizontal traffic light is showing green or red. More serious repercussions include being shut out of a dream job, like piloting planes, because misreading landing-strip lights can have life-or-death consequences.
Now, a host of new research and tools promise to improve life for the estimated 32 million Americans—8 percent of men and 0.5 percent of women—who have some degree of colorblindness.
For many, getting through the day—avoiding wardrobe perils and worse—has often involved bringing in a second pair of eyes. But new websites and smartphone apps offer to help identify or enhance hard-to-see colors. Video game manufacturers are increasingly including "colorblind" modes in their games. And researchers are homing in on more specific vision tests that may allow mildly colorblind people to qualify for jobs that, until now, have been closed to them.
A genetic test, made by Genevolve Vision Diagnostics, will soon be available that can identify the exact type of colorblindness someone has, which the company hopes could pave the way for customized tools.
A cure for colorblindness might even be in the offing. Vision scientist Jay Neitz and his colleagues at the University of Washington are building on their 2009 breakthrough in which they restored red-green vision in two colorblind squirrel monkeys by inserting the missing gene into a virus and injecting it into their retinas. Four years later, the monkeys, Sam and Dalton, still pass daily vision tests, identifying colors on a computer screen correctly. They also have a newfound liking for green M&M's, Neitz says.
He and his colleagues are working on a similar therapy for humans, but many hurdles remain.
"We know it's effective. The issue is whether it's safe," Neitz says.
Many colorblind people aren't even aware they have a "color-vision deficiency," as it's officially known, unless they apply for a job that requires precise color recognition. Even people with mild colorblindness can be barred from being pilots, air-traffic controllers, police officers, lab technicians and electricians—usually for safety reasons.
The term "colorblindness" is actually a misnomer.
"People think you're living in a black-and-white TV show and that's not true. There are all different degrees, from mild to severe. And you can see colors—they're just different," says Terrance Waggoner, an ophthalmologist consulting on color vision for the U.S. Navy.
But the impact does go beyond missing just one color.
"A colorblind person who can't see red can't see the red in purple—he just sees blue," Neitz says. Since red and green make brown, people with red-green blindness often have trouble telling the three colors apart.
The vast majority of colorblind people have trouble seeing red or green, due to a genetic defect in the color-sensing cells, called cones, at the back of the eye. About 75 percent of them are specifically green-deficient; another 20 percent are red-deficient.
Either way, the impact on their vision is so similar that it's considered one disorder, red-green colorblindness, which is the most common single-gene disorder in humans, affecting 1 in eight men and 1 in 230 women of Northern European descent world-wide (and slightly fewer in other racial groups).
Blue-yellow colorblindness is rarer and develops later in life, often brought on by aging, illness, medication or head injuries. Rarer still is achromatopsia, the inability to see any color.