– For the more than 10 million Americans with colorblindness, there’s never been a treatment, let alone a cure, for the condition that leaves them unable to distinguish certain hues.

Now, for the first time, two University of Washington professors have teamed with a California biotech firm to develop what they say may be a solution: a single shot in the eye that reveals the world in full color.

Jay and Maureen Neitz, husband-and-wife scientists who have studied the vision disorder for years, have arranged an exclusive license agreement between UW and Avalanche Biotechnologies of Menlo Park. Together, they’ve found a new way to deliver genes that can replace missing color-producing proteins in certain cells, called cones, in the eyes.

“I don’t think there’s any question that it will work,” said Maureen Neitz, 57, a UW professor of ophthalmology.

The new treatment — which may be tested in humans within two years — could be a boon for the 1 in 12 men and 1 in 230 women with color-vision deficiency.

The trouble occurs when people are born without one or more of the three types of color-sensing proteins normally present in the cones of the retina. The most common type is red-green colorblindness, followed by blue-yellow colorblindness. A very small proportion of the population is completely colorblind, seeing only shades of gray. Because they can’t perceive certain colors, they see hues in muted or different shades than people with normal vision.

Brian Chandler, 38, of Seattle, said he first noticed he was colorblind in seventh grade, when he started getting C’s and D’s on drawings in science class. “I was coloring green stuff brown and brown stuff green,” recalled Chandler, a traffic-safety engineer.

Colorblindness is often a genetic disorder. It affects mostly men, who can inherit a mutation on the X chromosome that impairs their perception of red and green. A much smaller fraction of cases are in women, who have two X chromosomes, which gives them a better chance of avoiding effects of any genetic defect.

Most people think of colorblindness as an inconvenience or mild disability. But the Neitzes say the condition can have profound impacts — limiting choices for education or careers, making driving dangerous, and forcing continual adaptation to a world geared for color vision.

“There are an awful lot of people who feel like their life is ruined because they don’t see color,” said Jay Neitz, 61, the professor of ophthalmology who confirmed in 1989 that dogs are colorblind, too.

People may not qualify as commercial pilots, for instance, if they’re colorblind. Other careers that can be limited include those of chefs, decorators, electricians and house painters, all of which require detailed color vision.

The Neitzes have focused on the disorder for years, first proving in 2009 they could use gene therapy to correct colorblindness in male squirrel monkeys, which are born unable to distinguish between red and green.

After preclinical trials are complete, Thomas W. Chalberg Jr., the co-founder and chief executive of the firm, said he hopes to move to human trials within one to two years and then seek FDA approval for the treatment.