Brain Turns Signal Sent By Chip into Image

Medics at the Oxford Eye Hospital and King’s College Hospital in London have partially restored sight of men with the aid of tiny electronic chip implant. Due to a genetic condition known as retinitis pigmentosa wherein the light-sensitive cells in the eye stop working, Chris James and Robin Millar lost their sight at birth. Bionic eye implants promise to help blind see and are identical to the cochlear implants that have been helping deaf hear.

Chips of 0.12 by 0.12 inches size were embedded in a tissue at the rear of the their eyes. These chips worked as defunct photoreceptors (known as rods and cones) converting light into electrical impulses. The vision aid is powered by a battery pack, which is positioned close to the ear and connected through a thin cable threaded within the skin.

Study subject James explained the moment of switching on the chip as a ‘magic moment’ when he witnessed flashing lights. Researchers are working on the framework that will enable subjects to interpret bright and dark spots to identify or distinguish things.

Retina Implant AG of Germany developed these sight restoration chips. In the earlier clinical trials, surgeons were testing similar chips to relieve individuals of their sense impairment. Eberhart Zrenner of the University of Tubingen, developer of Retina Implant AG, has been working to enhance the chip over the last decade with the primary objective of making it safer and portable.

A Finnish named Miikka Terho, who was also blinded by retinitis pigmentosa at childbirth, received earlier version of the Zrenner’s chip in 2008. With the aid of electronic chip, his vision ability improved considerably and he was able to distinguish an apple from a banana by sight.

Similarly, initial testing of chip with 1,500 light-sensing diodes and small electrodes that help stimulate nerves to create a pixelated image, has hinted at positive outcome. Until now, Chris James has been able to distinguish the outlines of the objects.