In the hotel when the terminator takes out his eye he puts sunglasses on. A few scenes later, it shows some close-ups of him (in the police station). Look closely at the left eye (the one that he took out). You can see that it's still there.
No kidding eh? Talk about a simple error to fix. I guess they figured the dark sunglasses would be enough. Maybe they should have used those mirror-glasses. It probably wouldn't have looked quite as menacing though. btw, did you notice how incredibly fake his face looked during that whole eye-taking-out scene. Even in that scene when he puts his glasses back on after removing the 'eye' you can see his two eyes as he checks his appearance in the mirror.