Scientists have cured red-green color blindness in monkeys, the Times of London reports. Researchers injected a virus containing L opsin, a gene that regulates the production of the red-sensitive light receptor—known as a “cone”—into the retina of red-green colorblind adult monkeys, according to a study published in Nature. Over a 24-week period, the light sensitivity of their new cones adjusted, and the monkeys could perform well on red-green color tests.
The red-green disorder is the most common type of color blindness in humans, and L opsin deficiency is usually the reason, which suggests that the therapy used in the study could be successful in humans. Critically, the monkeys’ adult brains were able to rewire themselves to use the information from the new red cones—the researchers had expected that only young brains would be adaptable enough to respond to the treatment.