Larry Hester was diagnosed with a degenerative disease called retinitis pigmentosa (RP) in his early 30s. At the time, there was no treatment available for the disease, so Hester could do nothing as his sight very rapidly disappeared for good over several months. More recently though, Hester was fortunate enough to be selected as one of just seven people in the US to have a ‘bionic eye’ fitted by researchers at Duke University's Duke Eye Centre.
The bionic eye is actually called an Argus II Retinal Prosthesis Device. The system comes in three parts - a small electronic device that's implanted in and around the user's eye, a tiny video camera that is attached to a special pair of glasses worn by the user, and a video processing unit that’s also worn or carried by the user.
When the user puts the glasses on and activates the device, the attached video camera starts capturing images of the surrounding area. These images are converted to an electrical signal, which is processed by the device's video processing unit. This signal is then delivered wirelessly to the eye implant, which electrically stimulates the user's retina. This stimulation is interpreted by the brain as dots of light that can be distinguished into different objects, including doors, street curbs, large written words or sentences, and people’s facial expressions.
Hester came into the Duke Eye Centre on September 10 to have his bionic eye fitted by retinal surgeon Paul Hahn, and came back three weeks later to have it activated. According to a press release from Duke, when the device was turned on and Hester was asked if he could see anything, he exclaimed, “Yes! Oh my goodness. Yes!”
While the device is not capable of restoring normal eyesight, it acts as a kind of visual aid that allows users to distinguish between different objects in front of them, such as a door or a wall, or a pedestrian crossing painted on the road. "During a clinic visit on Monday, Hester described “seeing” sights he had long believed were past memories – a white duck swimming in a pond, the harvest moon, his wife’s yellow chrysanthemums,” the team reports.
Hester will return regularly to the centre for check-ups and training, which will help him learn to distinguish a greater variety of objects based on the flashes produced by the device. “I just wonder how I have been so lucky,” he said. “Why me? But if I can use what I learn from this to help others with RP, it will not just be for my benefit.”