For the over-55 crowd, the risk of vision loss goes up. A new self-powered bionic eye being developed by a team of opthalmologists and physicists could help restore eyesight to older adults with severely limited eyesight.
The common condition, called age-related macular degeneration, destroys the most sensitive part of the retina located at the back of the eye. When that part goes, objects become so blurry that it's difficult to recognize faces, drive a car or read text. Retinal implants do exist, but they are bulky and require complex surgery.
A team from Stanford University and the University of Strathclyde in the United Kingdom has created a thin prosthetic chip from silicon that electrically stimulates neurons in the retina. Unlike other retinal implants, the device is photovoltaic so it wouldn't require complicated surgery for a battery-powered setup.
Daniel Palanker, associate professor of opthalmology and experimental physics at Stanford, along with UC Santa Cruz associate physics professor Alexander Sher and postdocs Keith Mathieson and Jim Loudin led the work, which was recently published in the journal Nature Photonics (abstract).
The prosthesis works in tandem with video glasses that record images and then project what's been captured onto the eye. As the BBC's James Gallagher reported, the glasses fire beams of near infrared light onto the retinal chip, creating an electrical signal that's then passed on to nerves. When the retina is stimulated this way, visual perception occurs.
Although they have yet to test it in humans, the group reported in their Nature article that the chip successfully stimulated degenerate retinas in rats.
"With our device, the surgeon needs only to create a small pocket beneath the retina and then slip the photovoltaic cells inside it," Palanker said in a description of the technology from the University of Strathclyde.
For those who have age-related macular degeneration, the federally-funded National Eye Institute suggests tools such as reading glasses with high-powered lenses, handheld magnifiers, and talking watches. Now that corrective laser eye surgery has become so common, I can easily imagine a day in the future when going in to get safe, effective bionic eyes is an expected part of getting older.
Photo: Projected image of a human retina. Scientists are developing a simple remote-controlled prosthetic version. Credit: Ralph Aichinger