The total loss of any one of our natural senses has an instant and devastating effect on a human being’s ability to function. Unfortunately, there are nearly 6.7 million American adults aged 16 and older who have a visual disability making it difficult to engage in normal activities even with the help of corrective lenses, according to the National Federation of the Blind. A total of 20.6 million Americans over the age of 18 have experienced vision loss, 15.3 million of those having suffered significant levels of vision loss, according to a 2012 report issued by the Center for Disease Control’s National Center for Health Statistics.
The eye has a complex engineering enabling the sense of sight which helps us to perceive the world surrounding us. Any complication in the cornea, which refracts light waves around the pupil, or the light-sensitive rods and cones of the eye’s retinal tissue can prove to be debilitating to anyone’s vision. Cataracts, macular degeneration and glaucoma are just a couple of the health conditions that can lead to a loss of vision. Although there are treatments designed to slow the progression of blindness, vision which has been lost is incredibly difficult to restore.
For those who have lost their eyes to injury, prosthetic replacements have existed for millennia. There are reports of an ancient artificial eye which was unearthed in the Iranian city of Shahr-e Sukhteh, also known as Burnt City, which may be 5,000 years old. The eye, made of tar and animal fat, is thought to be the world’s oldest prosthetic device. Egyptian and Roman societies shaped clay into ocular prosthetics while the use of glass eyes was pioneered much later by Venetians in the 16th century. In 1832, German glassmaker Ludwig Müller-Uri pioneered the development of cryolite glass, which was much more comfortable to those who required a glass eye prosthetic. Plastics were incorporated into the construction of artificial eyes after World War II, when American imports of German glass were ended and replacement materials were needed to craft ocular prostheses for injured soldiers.
Human civilization has long felt a need to design and fabricate solutions to the loss of an appendage, a subject we’ve covered in the past here on IPWatchdog. In recent years, digital technologies have laid the foundation for serious advances in the field of bionic prostheses. Last December, the Intellectual Property Owners Education Foundation (IPOEF) recognized Dr. Hugh Herr as Inventor of the Year for his development of foot and calf bionics.
Lately, there have been reports of technological advances which could make bionic vision a reality. One company, Occumetrics Technology Corp. of British Columbia, Canada, has been making a stir with claims of a bionic lens which could help recipients to see three times better than a human’s normal visual acuity, which we commonly refer to as “20/20 vision.” The lens can purportedly be painlessly implanted into a person’s eye in a procedure similar to cataract surgery. The company claims that the replacement operation could be performed as an outpatient procedure that takes less than 10 minutes to complete.
However, as we’ve already pointed out, the lens is not the only element of the eye which is crucial to our sense of sight. The rods and cones of the retina can become afflicted by a rare disorder known as retinitis pigmentosa (RP), a genetic condition which disrupts the normal production of proteins necessary for photoreceptor activity. The condition can result in difficulty seeing at night, loss of peripheral vision or, in some cases, complete blindness.
A very small number of people have received an implantable device which has allowed them to gain some semblance of sight. A device known as the Argus II Retinal Prosthesis System, developed by Second Sight Medical Products of Sylmar, CA, had been surgically implanted into seven patients as of October 1st of last year; the device was first approved by the U.S. Food and Drug Administration in February 2013 for patients with degenerative eye diseases. The system relies on the use of an electronic stimulator implanted into a recipient’s eye which receives a signal from eyeglasses which are outfitted with a video camera. The video is transmitted to the stimulator, producing a pixelated view that lets a person perceive basic shapes. Transmitting the signals in this fashion allows the Argus II to circumvent the dead layer of rods and cones and transmit light signals to the brain.
James Kelm of Duluth, MN, had lost his eyesight decades earlier before it was restored by a Second Sight medical implant during a procedure at the University of Minnesota this March. As was first reported by the Star Tribune, Kelm had difficulty making out an elevator door when his implant was turned on. Two months later, his ability to understand his new sense of sight had improved to the point that he was able to perceive people entering or leaving a room.
The Argus II system isn’t perfect beyond its inability to determine color or detailed shapes. In clinical trials, nearly two-thirds of participants had no adverse reactions but the remaining subjects each experienced on average two harmful outcomes each, ranging from retinal detachment to erosion of the conjunctiva, or the transparent tissue covering the eye. The device and procedure can cost up to $150,000, an incredible financial burden for most people. However, Medicare/Medicaid funding of the device was approved in August 2013, which has helped some people cover much of the procedure and technology’s expense.
There are a number of groups other than Second Sight which have striven to develop bionic technologies to reverse blindness or vision loss. A group of researchers at Monash University in Melbourne, Australia, have developed a bionic eye implant which the university expects will be used in human trials starting in 2016. This system is similar to Second Sight’s but instead of utilizing a retinal implant, a series of fingernail-sized ceramic tiles, each having 43 microelectrodes, are implanted directly into the brain’s visual cortex. Like the Argus II, this system uses a camera installed within a pair of glasses to record an image which is transmitted wirelessly to the implant.
Another condition that can afflict the retina is macular degeneration, a disorder that slowly damages the retina’s macula, which is responsible for the sharpness of vision in the center of our vision’s focus. This age-related condition can be exacerbated by smoking or through genetic factors. At this year’s annual meeting of the American Association for the Advancement of Science, a contact lens for treating macular degeneration was presented by a team of researchers from a collection of universities and private research firms. The larger lens, which covers part of the eye’s sclera, provides a telescopic function which enables magnified vision on a wearer.
Four decades after the American public grew enamoured of the fictional bionic technologies featured on the ABC Network’s television show The Six Million Dollar Man, mechanical systems developed for the human body have finally reached the point where we’re starting to at least approximate some very basic human functions. From bionic arms developed by DARPA to Dr. Herr’s foot and calf system to the sight restoring technologies discussed above, we’re entering a new day where science and technology starting to have the answers to some of the most terrible losses the human body can suffer.