Restoring vision to blind people has proven to be a particularly challenging task for scientists. However, new technologies combining an eye implant and glasses with a video camera may soon be available for disabled people.

Researchers have been developing such bionic eyes for decades, and in some cases spending hundreds of millions of dollars on engineering problems. One such device, designed to help people with rare eye conditions, is awaiting US regulatory approval. It is known as Argus II, made by Second Sight Medical Products in California. Other researchers, including those at MIT and Stanford University, are continuing to work on what they believe to be even more complex versions.

The Argus II product uses a device known as a retinal prosthesis, which bypasses dead or damaged cells in the eye to detect light. Instead, the device redirects visual data through the implant to the parts of the eye that are still working. Like other similar devices under development, it uses video cameras embedded in a pair of glasses to collect visual information in the form of light and send it to the implant in the form of an electrical signal.

If the Argus II is approved by the US Food and Drug Administration, it will be the first retinal prosthesis to hit the US market. The devices are already available in Europe.

Patients with retinitis pigmentosa, a rare disease that damages and kills cells in the retina, tissue at the back of the eye, are likely to benefit from these devices. It most often occurs in people with diabetes: their vision becomes more and more blurry, until eventually they are completely blind.