India, Oct. 6 -- In 2021, researchers reported that a 58-year-old man who had lost his sight to an inherited eye disease could locate and touch objects on a table in front of him, wearing special goggles. A gene taken from a single-celled green alga had been injected into one of his eyes. Last month, the US Food and Drug Administration accepted a licence application for a similar treatment.

That work traces back to the three scientists awarded this year's Nobel Prize in Physiology or Medicine on Monday. Karl Deisseroth, Peter Hegemann and Georg Nagel made discoveries that opened a new technique, called optogenetics.

Optogenetics uses light to switch living cells on and off, and it works the same way in a patient's eye as in a laboratory...