A tiny chip implanted into the eyes of people suffering vision loss from irreversible age-related macular degeneration has restored central sight in a dazzling first.

It's called the PRIMA system, tested across 17 European hospitals, and it restored central vision in 26 of 32 patients who used it for 12 months – many of whom could even read again. The result, developed by a large international team of doctors and scientists over many years, represents a massive breakthrough in treatments for vision loss.

"It's the first time that any attempt at vision restoration has achieved such results in a large number of patients," says ophthamologist José-Alain Sahel of the University of Pittsburgh School of Medicine, co-senior author on a paper describing the results.

"More than 80 percent of the patients were able to read letters and words, and some of them are reading pages in a book. This is really something we couldn't have dreamt of when we started on this journey, together with Daniel Palanker, 15 years ago."