No matter where you are or what you’re doing, your body relies on its eyes during every waking second of the day. The eyes play such a key role in our daily lives that it’s hard to envision (pardon the pun) living without them. Unfortunately, a sizable number of Americans must contend with a reduced or nonexistent sense of sight. Given that such problems afflict so many people, scientists have spent much time and effort on developing “bionic” eyes, devices that may at least partially restore the vision of certain individuals.
Glasses, Electrodes and Video Cameras
A prime example of this new technology is a system developed by Second Sight, a company based in California. Known as the Argus II, this device relies on several key pieces of equipment to operate, including a small video camera and a pair of glasses. In 2013, the US Food and Drug Administration (FDA) approved the use of the Argus II in adults who met specific criteria.
The way in which these “bionic eyes” work is relatively straightforward. First, the camera embedded in the glasses receives visual information from the surrounding environment. This data is then transmitted to a computer at the patient’s hip via a cable. The computer (called a VPU, or a video processing unit) takes the information and converts it into a set of instructions, which are immediately sent back to the glasses.
These directions are wirelessly transferred to an implant on the eye, which consists of a receiver and an array of electrodes. The receiver is tasked with handling incoming data, which it uses to send a corresponding signal cluster to the electrode array. In turn, the array sends electronic pulses to cells in the retina, a layer of tissue at the back of the eye.
The retina cells ship the electric pulses to the brain via the optic nerve. Finally, the brain transforms this information into patterns of light. Patients learn to interpret these patterns, allowing them to visually identify various aspects of their surroundings.
Living with New Eyes
Since the FDA has only recently given its blessing to the Argus II, only four Americans have been implanted with this device as of April 2014. One of these individuals is Michigan resident Roger Pontz. Pontz received his “bionic eye” after a 4 ½ hour procedure at the University of Michigan’s Kellogg Eye Center.
Before the procedure, the 55-year old ex-factory worker had long struggled with vision problems. As a teenager, Pontz developed retinitis pigmentosa, a condition that afflicts roughly 100,000 Americans. A hereditary illness, retinitis pigmentosa damages the patient’s eyes by attacking light sensitive retina cells. This degenerative disease slowly eroded Pontz’s eyesight, eventually leaving him nearly blind.
Of all the Americans with retinitis pigmentosa, only 7,500 meet the criteria for receiving the Argus II. Specifically, potential recipients must have end stage retinitis pigmentosa, and must have either little or no light perception in their eyes. Furthermore, all patients are required to be at least 25 years old.
After the device was implanted on his left eye, the former competitive lifter’s vision improved noticeably. For example, Pontz can now identify and pick up his pet cat, and can accurately detect the presence of his grandson. While Pontz still faces significant visual limitations, both he and his wife are astonished by his progress. Terri Pontz told the Associated Press (AP) that she “said something I never thought I’d say: `Stop staring at me while I’m eating,”‘
In order to reap the maximum benefits from his new implant, Pontz has regular check-ups with an occupational therapist at the Kellogg Eye Center. These appointments are geared toward triggering the visual memory of implant recipients, while also helping them get acquainted with their new “eyes.” For example, at a recent check-up, Pontz was told to place white and black plates in front of differently colored backgrounds. Pontz was then asked to guess the color of the plates.
While getting the most from the Argus II will require much effort, Pontz is already impressed by the device’s impact on his life, telling the AP that he “can walk through the house with ease. If that’s all I get out of this, it’d be great.”