My grandpa had a glass eye most of his life; people who knew him for 20 years were surprised to learn that this was the case at his funeral. I'd rule it as the same test to spot cyberlimbs (visual perception with a threshold of 3 or 4) with an even higher threshold to spot them with the naked eye; millimeter wave, MAD scanners, and the like would probably pick them up as easy as anything though.
Maybe thermographic vision as well - given that it's unlikely anyone will be touching your eye, they could be appreciably cooler than a real one.