Loss of an eye shouldn't be loss of crits. You shouldn't lose perception either. Columbo was very perceptive.
While you have not explicitly said what this pertains to, you still should add a disclaimer of a possible spoiler.
There are actually two ways to loose an eye, at least as far as I am aware.
Does seem a bit extreme, but would be nice it is rewarded later on in some way.
In Columbo's case it gave him a modifier, though: you never saw him engage in ranged combat but he did gain points in charisma and wisdom. There's a lot to be said for being scruffy.
Talking of which, ISTR he drove a Buick Skylark for a bit. I borrowed one that was even more disreputable-looking than his. It was awesome from that point of view, as well as its sort of "anti-Tardis effect" where it was very much smaller on the inside than the outside, but overall it was an incredibly horrible car.
Columbo was perceptive, yeah, but also while Peter Falk had a glass eye, I'm not sure the character Columbo was supposed to be missing an eye. That said, I do feel a loss of ability to crit hit is a bit severe.