The Hargrave Eye Center’s latest post:
It is estimated that around 36 million people are legally blind, and an additional 217 million have moderate or severe impairment to their vision. Though it’s believed that a significant amount of impairment can be prevented, there is no known cure for blindness; bionic eyes may provide a means of redefining what it means to see.
Prosthetic eyes, often known as “glass” or “artificial” eyes, only replace the eye physically to mimic the appearance of the removed part, whereas bionic eyes grant the wearer the ability to perceive their world without replacing the existing physical structure. There are, of course, significant limitations to the capabilities of such technology, but the bionic eye is a great step towards restoring sight in those who experience some form of low vision or blindness.
So far, only one model of bionic eye, the Argus II Retinal Prosthesis System created by California-based company Second Sight, has been approved by the American Food and Drug Association (FDA). This bionic eye cannot help everyone, however. The effectiveness of the apparatus is dependent on the cause of blindness. The bionic eye has been designed mostly for treating Retinitis Pigmentosa (RP), a fairly rare group of genetic disorders that leads to the deterioration of cells in the retina but leaves the connected nerves intact. Work is being done to treat more common causes of blindness, like degenerative conditions, but current technology limits what is possible.
The bionic eye is not designed to cure blindness; rather, it provides a means for those affected by severely impaired vision to navigate the world through recognizable light patterns that depict movement and shapes.
How It Works
The Argus II is composed of a retinal implant, a pair of glasses with a camera, and a video processing unit (VPU). The implant is surgically placed on the retina, and it features 60 micro-electrodes that stimulate nerve reactions which no longer occur naturally. The camera communicates electrical signals to the implant, which then stimulate the connected nerves. The resulting pattern of light produced by the relay of information between the nerves and brain replicates the images a fully-functional eye would perceive.
The facilitated “vision” is not identical to average sight, however. While the technology is far from perfect, and in order to replicate “normal” vision the device would need a significantly higher number of electrodes (a number estimated to be around one million), the advancement in restoring or replicating sight is astounding.
James Kelm, one of the world’s first people to receive the Argus II implant, described his new vision as “chaos,” but he was amazed that for the first time in more than two decades, he was able to make out moving shapes and identify his wife, whom he had never seen. He compared the flashes of light to a night sky full of stars, and that learning to understand the patterns is comparable to “learning how to identify the different constellations.”
There is still room for improvement, but the existing bionic eye is certainly an indicator of significant technological development in regards to the treatment of blindness. Presently, there are many limitations to what the Argus II and other bionic eyes in development can do and how much more progress can be made on the project. Still, the success so far suggests that science and technology are moving in a direction where those without sight will soon be able to navigate the world with more ease.
from Hargrave Eye Center |Ocular Health Experts https://ift.tt/2MLj0yI