Robert J. Johnston Jr.

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Lab-grown retinas reveal how the eye builds its sharpest vision

Leading the retinal organoid program at Johns Hopkins

The foveola is a sliver of tissue at the very center of the retina, and the researchers say it accounts for roughly half of human visual perception. It also has an odd composition: it holds red and green cones but no blue ones. Johns Hopkins scientists grew that region in a dish and watched it assemble itself, then described a mechanism that contradicts an explanation the field has used for about 30 years.

Updated Oct 31

Notable Quotes

First, retinoic acid helps set the pattern. Then, thyroid hormone plays a role in converting the leftover cells. That's very important because if you have those blue cones in there, you don't see as well.

from Lab-grown retinas reveal how the eye builds its sharpest vision · Updated Oct 31

We can't really rule that out yet, but our data supports a different model. These cells actually convert over time, which is really surprising.

from Lab-grown retinas reveal how the eye builds its sharpest vision · Updated Oct 31