Braille to Sight: Opus Genetics' Gene Therapy Treats Rare Childhood Blindness

“What does the letter ‘E’ look like?”

That was the response of an adult patient who had been blind since the age of two when asked whether he could see the letter on the Snellen chart—the familiar poster with rows of letters shrinking in size that hangs in every optometrist’s office.

It wasn’t that he couldn’t see the letter on the chart. It was the first time he had ever seen a letter. His world, until then, had been known through touch and sound. Letters were understood by the ridges of braille beneath his fingers, not by the black shapes against a white background. For that matter, he hadn’t seen anything before—not his food, not the face of a family member, not a game of soccer. He hadn’t been able to cross streets or call an Uber without help. Then, after receiving a one-time inject