The thing is, according to sources, the reason her eyes are like this isn't because she's a cyborg or anything. It was done to apparently match the same style done in the manga/OVA. That's where the problem lies. The character is not supposed to look so inhuman that she becomes uncanny. Her eyes are relatively large in the manga/OVA because it is a stylized point.
James Cameron and Rodriquez, those working on the film, did this because they again, wanted to match that style. Which doesn't work here. It works fine in a manga/anime/cartoon setting where things can be enhanced, but here, it only looks freaky and off.
It would be the equivalent of if you were watching One Piece or something and then this photo realistic pirate came up and starting fighting Luffy and you had to take it dead seriously. There are things that simply work in one setting that don't work in another and this is a perfect example of something that doesn't work.