Retinal implant restores partial sight to blind people

Some previously blind patients fitted with retinal implant could read signs, tell the time and distinguish white wine from redBlind people have described smiles on friendly faces, the food on their plates, and household objects from telephones to dustbins, after surgeons fitted them with electronic chips to partially restore their vision.Results from the first eight patients to enrol in a clinical trial of the retinal implants show that five found the chips improved their eyesight enough to be useful in everyday life.All those involved – men and women aged 35 to 62 – had lost their sight to retinitis pigmentosa, a hereditary disease that destroys the light-sensitive cells in the eye. The chip stands in for the defunct cells by detecting light rays and converting them into electrical pulses, which are sent along the optic nerve to the brain.Each patient spent up to 10 hours in surgery to have the 3mm by 3mm chip implanted in one eye. The chip is studded with 1,500 light-sensitive elements that pick up light falling on the macula, the most light-sensitive part of the retina (if you're reading on a mobile device, click here to see a video of the retinal implant).The chip does not restore vision fully. Instead, patients see light and dark patches in a small part of their visual field, as if they had black-and-white tunnel vision. Though limited, some could read signs on doors, tell the time on analogue clocks and distinguish white wine from red, for example. One patient made ...
Source: Guardian Unlimited Science - Category: Science Authors: Tags: World news Health guardian.co.uk Medical research Human biology Society Neuroscience UK news Disability Blindness and visual impairment Source Type: news