I imagine that very nearly all of the readers of Science in My Fiction are familiar with the Star Trek: The Next Generation character Geordie Laforge and his VISOR.
The VISOR scans the electromagnetic spectrum, then transmits its information to the brain of the wearer via the optic nerve. Something very similar was approved for sale earlier this year. The Argus II uses a video camera to capture the visible portion of the electromagnetic spectrum, then processes that information and transmits it wirelessly to an implant on the user’s retina. The device only works for those suffering from retinitis pigmentosa, a degenerative disease that damages retinal photoreceptors, but leaves the rest of the retina.
The Argus II is extremely crude compared to the VISOR, but nonetheless it allows people with limited or no vision to perceive light and dark at sufficient resolution to find doors and locate objects, restoring basic visual function. The company making the Argus II is actively working on developing improved models with greater resolution and better sensor configurations.
Someday maybe they’ll even come up with something as good as science fiction.