I understand that, but you put it in a way that cyclops can't show emotions with their eye for some reason, while they do. It may not be as expressive, since you'll have just one brow instead of two, but to detect frowning, shock, calm and other signals is very much possible. Actually, even having 2 eyes but positioned slightly off will already make you feel uneasy, same as having one eye or an actual tail on what seems to be a regular human. If we going that deep into psychology, then all monster girls are at fault, because projecting any of them to reality will create an uncanny valley effect one way or another.