Pioneering eye implants!

Two British men who have been completely blind for more than a decade have had their sight partially restored thanks to an electronic chip implant allowing them to perceive light and make out basic shapes, for example distinguishing between a straight and curved line. Although the development seems small it is understandably extremely significant to someone how has seen nothing but darkness for years and it is hoped that the sight will improve over time.

Both men lost their sight due to retinitis pigmentosa which is described as when the photoreceptor cells at the back of the eye gradually cease to function. The 3mm electronic chip takes over the photoreceptor cells function, the chip contains 1500 light sensitive pixels and was placed behind the retina in both patients. A fine cable runs to a control unit which is situated underneath the skin behind the ear.

Light rays stimulate the pixels to send electronic signals to the optic nerve and these signals then travel onto the brain. These signals cause the brain to receive flashes of light rather than conventional vision and images are in black and white. The trial is in its early stages and the patients must learn to interpret the signals sent to their brain, hopefully this will then improve the detail which can be seen.

Another unique aspect of this development is that the device is portable, unlike the chip received by a Finnish man in 2010 which only worked in laboratory settings.

As of yet stem cell research related to restoring eye sight has only included people with residual vision where as these trials involve two patients who previously had no vision whatsoever.