SAN FRANCISCO — Patients blinded in one or both eyes by chemical burns regained their vision after healthy stem cells were extracted from their eyes and reimplanted, according to a report by Italian researchers at a scientific meeting.

The tissue was drawn from the limbus, an area at the junction of the cornea and white part of the eye. It was grown on a fibrous tissue, then layered onto the damaged eyes. The cells grew into healthy corneal tissue, transforming disfigured, opaque eyes into functioning ones with normal appearance and color, said researchers led by Graziella Pellegrini of the University of Modena.

The stem-cell treatment restored sight to more than three-quarters of the 112 patients treated, Pellegrini said this week at the International Society for Stem Cell Research meeting. The patients were followed for an average of three years and some for as long as a decade, Pellegrini said.

“The patients, they are happy, even the partial successes,” she said in San Francisco. “We have a couple of patients who were blind in both eyes. Can you imagine for these patients the change in their quality of life?”