Eye implant helps blind patients 'read' Braille

Posted by Flora Malein

A new device that allows blind patients to see words by stimulating the light-sensitive part of the eye has been developed by researchers.

Braille patterns were streamed directly into a patient's retina, allowing him to read four-letter words accurately and quickly.

Called the 'Argus 2', the device is based on a microchip containing electrodes implanted into the retina at the back of the eye.  The patient wears a portable processor and a small camera mounted on a pair of glasses.
 
An image, such as a four-letter word, from the camera is translated into electrical impulses via the portable processor. The microchip in the eye receives these impulses via a receiver, allowing it to stimulate patterns directly onto the eye’s nerve cells using a grid of 60 electrodes. 
 
The device, which has been developed by the company Second Sight, has been implanted successfully in over 50 patients, allowing many of them to sense objects, movement, and even colour. The findings from the study are published in the journal, Frontiers in Neuroprosthetics.
 
"In this clinical test with a single blind patient, we bypassed the camera that is the usual input for the implant and directly stimulated the retina," says senior research scientist Thomas Lauritzen of Second Sight.
 
"Instead of feeling the Braille on the tips of his fingers, the patient could see the patterns we projected and then read individual letters in less than a second with up to 89 percent accuracy." 
 
The device marks yet another development in new technologies that are working towards helping people regain their sight.  Research earlier this year announced that scientists are close to developing a retinal implant that could restore normal vision to some blind patients.
 
The Argus 2 is primarily aimed at patients with the genetic disease Retinitis Pigmentosa (RP). While its capabilities remain limited to large conventional letters and short words, the developers believe that future versions could be improved with the addition of letter recognition software.