Scientists at Imperial College London and University of Manchester have found how to make eye cells sensitive to light, opening new ways to treat some forms of blindness and help people who get depressed as the nights draw in.

The eye’s retina contains photoreceptors that interpret light levels to allow us to see. Much human blindness is due to diseases of the retina in which the photoreceptors are destroyed.

Until recently, experts had thought there were only two types of photoreceptors – rods and cones.

But experiments on mice which have had their rods and cones destroyed, reveals that other cells in the retina also have some form of light response. Turning on a gene for a pigment called melanopsin caused nerve cells to work like photoreceptors.

So melanopsin genes could be inserted into intact cells in otherwise diseased retinas, turning them into functional photoreceptors.

However, this would probably not fully restore the sight.

“The resulting ‘vision’ may well be little more than black and white light sensitivity, but it would be a start,” explained Ron Douglas of London’s City University.

Via BBC News and Nature.