Posted: Dec 19, 2016 1:02 pm
The main biological problem with that is that an eye needs a lot of blood if it is not to fail quickly. so it wouldn't get enough at the tip of a finger. I suppose you could keep your hands in your pocket nearly all the time, but I would prefer that the extra eye was attached to a certain appendage that already has a rich blood supply. Sadly, that rules out about half the population, but I'm hoping that this idea might stand up to scrutiny.