Progress continues in the components of prosthetic sight, with replacements for age-damaged retinas being the most advanced at this time. The latest versions are a few years from human trials, and the result is far from a full restoration of vision, but it's a great improvement over blindness. The technology will only get better with time: "The implant is based on a small chip that is surgically implanted behind the retina, at the back of the eyeball. An ultra-thin wire strengthens the damaged optic nerve; its purpose is to transmit light and images to the brain's vision system, where it is normally processed. Other than the implanted chip and wire, most of the device sits outside the eye. The users would need to wear special eye glasses containing a tiny battery-powered camera and a transmitter, which would send images to the chip implanted behind the retina. The new device is expected to be quite durable, since the chip is enclosed in a titanium casing, making it both water-proof and corrosion-proof. The researchers estimate that the device will last for at least 10 years inside the eye."