Patients blinded by advanced macular degeneration have regained the ability to read with the PRIMA retinal implant.

The system pairs a two-square-millimetre photovoltaic chip under the retina with camera-equipped glasses.

The glasses project near-infrared light onto the chip, which turns it into electrical signals for the brain.

In the PRIMAvera trial of 38 people, patients gained an average of 24.5 letters on an eye chart at 12 months.

More than 80% could read, do crosswords and use their phones after visual training.

At 36 months, the 18 patients still evaluated averaged 29 letters gained, bringing vision to about 20/120.

The three-year data came from a conference presentation, not a peer-reviewed paper, and the trial had no control group.

Made by Science Corporation, PRIMA is approved in Europe but still awaits US FDA clearance.

Read the full article for more details on the PRIMA implant.