Your username is Kerry so I'm going to assume your a girl but either way I would say if you are an above average looking guy/girl it won't likely sent your looks much. However most people are average everyday looking and there I think it can be a negative in terms of looks.
Again it depends on style to face shape. I think Specsavers do some digital thing in store where they can choose the best shape glasses for your face shape.
Main thing I thing for girls or guys is that they can make you look geeky/nerdy. This is probably more so with the wrong shape glasses for face shape. I personally think smaller framed glasses look better on women. For some reason big framed glasses seem to be more in fashion but they can make a girl look real bad.
All in all they tend to be seen in a more negative light I think.
I've had laser surgery done (LASEK) I went to Moorfields & paid nearly £5k to get the job done. A good job was done of it and I now don't need glasses at all. I glad to be free from glasses as they can be a pain. However I wouldn't say they make a lot of difference in terms of who is attracted to you, none at all really. So while a bad pair of ill-suited glasses may do you no favours I don't think in general they really affect attraction matters much.