Way back when, before DSLRs, Canon had the EOS 5 (that’s the A2E to those in the USA). It was a pretty decent camera. My dad owned one. But one of the things it did which no other camera on the market could do, was eye-controlled autofocus. This wasn’t like the Eye AF we get today where the camera focuses on your subject’s eye. No, this was where the photographer used their eye to look at what they wanted the camera to focus on.
It was only ever used in a small handful of Canon’s 35mm SLRs before the idea seemed to be abandoned. But now, it looks like Canon might be reintroducing the system. Canon recently filed a patent (Japanese patent #2019-129461) for a very similar system so the folks at DPReview decided to do a little look back on the system and what it might mean for the future.