Sept. 16, 2009 — A rainbow of hope for people who are color-blind: New research suggests that gene therapy could one day give such patients the ability to see in full color.

Color blindness, also called color vision deficiency, occurs when photoreceptors in the eye’s retina lack certain light-sensitive pigments. It is most often hereditary and present at birth. People with this condition can’t distinguish between different shades of certain colors, or cannot see them at all. Red-green color blindness is the most common type of color blindness.

There is no cure for inherited color blindness. But scientists have shown that placing certain color-recognizing (photopigment) genes into eye cells of male monkeys known to be red-green color-blind allows the animals to tell the difference between the two colors. The photopigment genes are found in some female monkeys but never in male monkeys of this type. The scientists tested the monkeys’ vision by having them perform a computer-based color vision test.

The study authors say their findings demonstrate that the brain might be able to reprogram itself when given new sensory information, such as color-recognizing receptors, even when the key period for brain development is over. Until now, it’s been assumed that treatment for inherited vision disorders could only be done in very young patients.

The researchers say their findings could one day lead to new methods for curing adult vision disorders.

The study appears this week in the online version of Nature.