Man aids research learning to see again

After 43 years of blindness, Michael May can see again.

He can play soccer with his sons, enjoy movies and, for the first time, gaze on the Sierra Nevada slopes he has expertly skied — sightless — since the late 1970s.

But Mr. May can’t recognize his sons, Carson, 11, and Wyndham, 9, by their faces alone. Nor can he readily identify his wife, Jennifer.

People “can’t fathom that,” said Mr. May, who owns a company in Davis, Calif., that makes navigational software for the blind.

Three years after surgery restored sight to Mr. May’s right eye, researchers say his case shows how vision is more than just eye function. Blindness has long-term effects on how the brain processes information and constructs one’s view of the world.

Mr. May lost his sight to a chemical explosion when he was 3 years old. He eventually lost his left eye and remained blind in his right until the surgery in 2000.

But testing since that surgery has showed that Mr. May’s ability to interpret what he sees through his good eye is decidedly mixed, said Ione Fine, lead author of a study appearing in the September issue of the journal Nature Neuroscience.

Mr. May can identify simple shapes and colors. He can interpret objects in motion. He can spy faraway peaks. He marvels at the vibrancy of plants and flowers unseen since he lost his vision.

But three-dimensional perception and the ability to recognize complex objects such as the faces of family and friends remain severely impaired. He strains to tell the difference between a man and a woman. He describes a cube as a square with extra lines.

Written history mentions perhaps 30 people who reacquired vision after protracted periods of blindness, said Miss Fine, a neuroscientist at the University of California, San Diego.

She and her colleagues leapt at the chance to study Mr. May and began testing him just months after his cornea- and stem cell-implant surgery. The stem cells formed a protective layer over his new cornea to prevent clouding.

“There has always been this question: What would happen if a blind man got his vision back? Is it something innate or is it something we learn from first principles?” Miss Fine asked. “Is it something that happens or is it something we learn, like language?”

Repeatedly, the researchers combined vision tests with scans of Mr. May’s brain activity to study how blindness had affected him.

When asked to identify a cube illustrated on a two-dimensional computer screen, for example, Mr. May failed. But once Miss Fine commanded the cube to rotate, simulating motion in three dimensions, he immediately recognized it.

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