An estimated 45 million people in the world are blind. A multitude of factors cause blindness. Amongst the greatest are genetic disorders, such as retinitis pigmentosa, which affects over 2 million people worldwide, and macular degeneration, which affects 14 percent of people over the age of 80. One solution to this? Bionic eyes.
Creating artificial vision through the use of bionic eyes is no longer science fiction. The emergence of prosthetic limbs paved the way for scientists to experiment with prosthetic eyes. While a vast number of designs and variations are being pursued, they all target genetic blindness and create vision through electrical stimulation.
To understand how bionic eyes work, one must understand what causes most genetic blindness. Vision loss is often attributed to the progressive degeneration of photoreceptors located on the outside of the retina. Photoreceptors are tightly packed membranes containing the photopigment rhodopsin. When light hits it, a series of chemical reactions stimulates your retina and sends electrical signals to your brain, creating vision. When photoreceptors become dysfunctional, the light that goes into our eyes can’t be converted into electrical signals, causing blindness.
Theoretically, the more electrodes placed in the retina, the more one can electrically stimulate the neurons around it for better vision
That’s where bionic eyes come into play. Bionic eyes are actually just sunglasses with a camera attached to them, not actual artificial eyes. The camera continually captures images, converts them to radio waves, and sends them to the electrode implant in your retina. The implant stimulates the surrounding neurons in your retina, which send the signal along the visual pathway to the brain.
Theoretically, the more electrodes placed in the retina, the more one can electrically stimulate the neurons around it for better vision. However, there is such a thing as too much electrical stimulation. An experiment done by a German company, Retina Implant AG, in 2015 found that an array of 100 electrodes produced worse vision in their subjects compared to those with an array of 64 electrodes. The issue is that when one stimulates the neurons in one area of the visual pathway too much, vision starts to get blurry and fuzzy, making bionic eyes difficult and intricate to advance.
The bionic eyes we have today provide minimal, yet definitive vision to those visually impaired. Improving them will be difficult, but scientists have done the impossible in the past, so there is hope they can do it in the future as well.
Progress in Brain Research (2011). DOI: 10.1016/B978-0-444-53355-5.00001-4
Good article and I think science could make this leap.