When asking a girl out, whatever you do, DON'T ASK HER!
No, you don't need to adjust your computer screen or get new glasses. You did read that correctly. If you say "Do you want to go out with me?" or "Do you want to go see a movie with me?" you are immediately at her mercy. She can now say yes if she likes you, or if not, she might reject you (ouch!).
On the other hand, if you phrase it as a statement rather than a question, then she can only say yes, because if she says no, well that's ok because you never asked her anyway. Just say something like "We should get together sometime and do something". One other advantage is that by not specifying a time and place you have taken away the "maybe some other time" phrase, which is really a rejection.