Kiara Eldred sometimes compares her nine-month scientific experiments, growing tiny human retinas in a laboratory dish, to raising children.
Eldred, a graduate student at Johns Hopkins University, starts by growing thousands of stem cells and feeding them nutrients and chemicals that will steer them to develop into the retina, the part of the eye that translates light into the signals that lead to vision. 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.
After nine months of assiduous care, Eldred has a batch of miniature human retinas that respond to light. But growing the organoids is only the first step.
In a new study in the journal Science, Eldred and colleagues described using this system to understand a fundamental question about vision: How does color vision develop?
