Vision is a prismatic creation of nature. Being able to observe the rising of sun, the flight of a pigeon, the sight of a gigantic mountain covered with snow, the beauty of a lake and the mellow scene of sunset is a gift from nature. There is a quote
“If you can see, you can have it”.
Visual observation lays a groundwork on which our daily action rely on. If you tell someone a story of a person achieving something astonishing, he or she will not believe you unless you present a visual proof. That’s how much we depend on our eyes. Imagine a life without vision, a life reliant on on a walking stick and most importantly a life at the mercy of other people.
Today, more than 40 million people are suffering from loss of vision and almost 142 million are suffering from low vision. In past scientists had come up with a lot of ideas including prosthetic eye, retinal implant, lens replacement, laser surgery and so on to restore the normal vision and improve the quality of life. Bionic eye, approved by FDA, is a hope for blind people now a days. The only model of bionic eye that is available for the patients who are suffering from some kind of retinal disease such as retinitis, detached retina, retinitis pigmentosa and retinal degradation associated with age. The latest available bionic eye is Argus 2 with 60 electrodes.
How does normal eye work?
Light enters the eye through the bulge of cornea in front of the eye. Passing through aqueous humor, light reaches the pupil, a small opening in iris. Light then passes through convex lens and converges on the macula of retina. Macula processes the minute details of the visual signal and fovea, a small area on macula, processes further tiny details. Signals then transfer through optic nerve, optic chiasm and reaches the lateral geniculate nucleus in the brain on the posterior surface of thalamus. From the lateral geniculate nucleus, signals move toward the occipital lobe, the visual center of the brain. If anything goes wrong along this pathway, vision will be compromised.
How does bionic eye work?
The bionic eye consists of a camera and an implant. Implant is present on the retina with 60 electrodes that receives visual signals collected by camera and stimulates cells on the retina, more specifically the macula. This information is then processed through different layers of the retina and transfers to the occipital lobe of the brain through normal visual pathway.
Bionic eye can be a light of hope for people suffering from structural abnormalities of eye, retinitis pigmentosa or any other disease related to retina, laser surgery complications such as myopia ,decrease in visual field and person who cannot focus light properly due to age related degeneration of retina.
Limitation of bionic eye:
The limitation of bionic eye is that it contain only 60 electrodes that can stimulate only a limited number of retinal cells. So, patient can miss the details of visual field. Yet with bionic eye, person can cross a road without any support and can read a book with bold letters. Bionic eye is also not cost effective.
Bright side is that, it is refining and an ever expanding hope for blind people. Company is working on adding more electrodes to improve vision by stimulating more retinal cells.