Blind man sees after two decades - 7th June 2021

A totally blind man’s sight has now partly returned. He has been treated using particular proteins first found in algae. These are types of plants that live in water.

The therapy that scientists worked with is known as optogenetics. It makes use of special algae proteins which are sensitive to light, to control cells at the back of the eye.

The anonymous patient lives in northern France and he was treated by specialists in Paris. He initially found out it was working after realising he could see the painted stripes of a pedestrian street crossing. Now the person is able to count and also to identify objects placed near him.

The man's blindness was caused by an eye condition named retinitis pigmentosa, which he developed 40 years ago. This causes eye cells which sense light on the surface of the retina to die. More than two million people suffer from this condition globally. Although it is rare to lose sight totally, this man had been blind for the past 20 years.

Because the treatment took time to begin functioning, the man felt frustrated. Seeing the stripes of a street crossing was therefore a dramatic development. Dr José-Alain Sahel, from the Institute of Vision, Paris, said, "you can imagine he was very excited. We were all excited."

Perfect vision will not return to the man. However, the difference between having no vision and even limited vision can transform people's lives.