A cure for colorblindness might 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, Dr. 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," says Dr. Neitz