The implant is based on a small chip that is surgically implanted behind the retina, at the back of the eyeball. An ultra-thin wire strengthens the damaged optic nerve; its purpose is to transmit light and images to the brain’s vision system, where it is normally processed. Other than the implanted chip and wire, most of the device sits outside the eye. The users would need to wear special eye glasses containing a tiny battery-powered camera and a transmitter, which would send images to the chip implanted behind the retina. The new device is expected to be quite durable, since the chip is enclosed in a titanium casing, making it both water-proof and corrosion-proof. The researchers estimate that the device will last for at least 10 years inside the eye.
The scientists explain that the bionic eye will be affective for individuals who once had sight, since their brain knows how to process visual information. The unfortunate people who were born blind do not have the neurological capability to process the data received via the wire. Furthermore, the optic nerve must be at least partly functional. Otherwise, the data will not be fully processed. For many individuals that were born blind, this is a problem as well, since their optic nerve has never been used. However, most of these individuals have a natural compensation mechanism, in the form of enhanced senses, such as hearing and touch.
Although the device will not be able to restore the eye sight of the entire blind community, researchers are certain many people will benefit from the technology. For instance, age-related macular generation is the leading cause of blindness in the industrialized world, with about 2 million Americans currently suffering from the condition. The new technology will hopefully assist people suffering from this condition, and individuals suffering from retinitis pigmentosa (a genetic condition), but will not help glaucoma patients.
The researchers note the device has some limitations, and it will not restore perfect vision. However, they are sure it will give people the advantage of having a general sense of their surroundings. Hopefully, the technology may enable people to recognize faces and facial expressions. “The thing is to significantly improve the quality of life for blind patients,” said Joseph Rizzo of the Massachusetts Eye and Ear Infirmary, who has co-directed the project with MIT‘s John Wyatt since 1988.
This summer, the researchers plan to test the implants on animals. Within the next few years, they hope to start performing human trails. Wyatt says: “What level of achievement that would actually be is hard to know; but the idea is of not having to use the white cane – to walk around, find the sidewalk, avoiding a telephone pole. Being able to navigate safely in an unfamiliar environment, that’s the big topic.”
TFOT has covered the discovery of the last retinal movement-detecting cell and the latest stem-cell research that has improved our understanding of blindness. Another article recently published by TFOT deals with mind controlled bionic limbs, which were designed to assist disabled people in their daily lives.
Thirty six researchers joined collaborated on The Boston Retinal Implant Project, including scientists from MIT, the Massachusetts Eye and Ear Infirmary, and the V.A. Medical Center in Boston. For more information about the project, see the Boston Retinal Implant Project website.