Researchers in Paris injected one of his eyes with a gene for a light-sensing protein borrowed from algae, then trained him for months to use goggles that convert a camera's images into pulses of amber light his retina could now detect.
Wearing the goggles with his treated eye, he regained the ability to perceive, locate, count and touch objects placed in front of him, including a notebook, a smaller box, and the stripes of a street crosswalk. Without the goggles, or in his untreated eye, none of that was possible.
He could not see color or fine detail, and the result comes from a single patient, so it is a documented case rather than a replicated trial, and how well the approach would generalize to other patients with the same disease is still being tested. The study nonetheless marked the first time this gene-and-light technique restored any visual function in a blind human.
Read the original study
Sahel et al., Nature Medicine, 2021 · doi.org/10.1038/s41591-021-01351-4
Light reached a retina after four decades.
Source
- Sahel, J.-A., Boulanger-Scemama, E., Pagot, C., Arleo, A., Galluppi, F., Martel, J. N., Esposti, S. D., Delaux, A., de Saint Aubert, J.-B., de Montleau, C., Gutman, E., Audo, I., Duebel, J., Picaud, S., Dalkara, D., Blouin, L., Taiel, M., & Roska, B. (2021). Partial recovery of visual function in a blind patient after optogenetic therapy. Nature Medicine, 27(7), 1223–1229. https://doi.org/10.1038/s41591-021-01351-4