Being colorblind is a fairly common genetic variation. Color vision deficiency (CVD) affects around 1 in 12 men worldwide and 1 in 200 women; generally these individuals get along just fine. With inventions like colorblind-friendly design and glasses that allow color vision deficient individuals to see more of the spectrum, they have options. But what if we actually cured colorblindness permanently?
Humans have been working on curing colorblindness for years. Back in 2009, it was announced that two squirrel monkeys who were red-green colorblind since birth were able to see red and green as if they had never been colorblind. How? Gene therapy. The researchers used an injection of a neutralized virus combined with human genes for red photopigments. The injection was placed in the monkeys’ eyes, just behind the retinas. The neutralized virus would replicate to other cells within the eye, multiplying the genes for red photopigments with it. And it worked.
Five months later, the monkeys Dalton and Sam could see red. Two years later, the effects had lasted with no negative effects. Could this be used on humans one day in the near future?
Much more recently, researchers have turned to stem cells in an effort to cure colorblindness. Researchers from Johns Hopkins University, the University of California, San Diego (UCSD), and the National Institute of Mental Health have released some updates on their break-through testing. Johns Hopkins grad student Kiara Eldred was one of the researchers stimulating stem cell growth in the lab into forming functional human retinas. She told The Washington Post:
After two weeks of painstaking cultivation, those cells typically generate 20 to 60 tiny balls of cells, called retinal organoids. As they mature, these nascent retinas get dirty and slough off lots of cells, so they also need to be washed off when they’re fed every other day—at least for the first month and a half.
Overall it took about nine months to grow a functioning batch of retinas. Not only has this been posited as a possible cure for colorblindness, it’s given the researchers plenty of interesting data about the development of color vision.
For those wary about stem cell research, ethical uses are around the bend. The team at Johns Hopkins hope in the future to be able to take a few cells from an individual, convert them to stem cells, and then stimulate growth of the stem cells into the tissue they need. As the technology improves, researchers are hopeful that this kind of therapy could lower costs of treating expensive, devastating forms of blindness in all manner of patients.