I think Canon's Eye Control AF is a gimmick, because it's still too hit-and-miss (and more miss than hit)

Illustration depicting a photographer using Canon's Eye Control AF.

Canon's Eye Control AF technology was first introduced way back in 1992 on the EOS 5, but it wasn't quite the party trick it promised to be and was phased out.

Fast-forward to 2021 and it was reintroduced in the Canon EOS R3, where it pretty much did what it said it would do, but there were plenty of caveats, like it not working effectively if ambient light conditions were constantly changing. Another proviso was spectacles (and potentially even contact lenses) impeding its proper functioning.