When you begin your training here in Denmark the military will accept -1/+1, no more, whether training for fast jets or whirlybirds. -1/+1 of course has to be corrected by either glasses or contacts.
However, it depends on a lot of things, like for instance the doctor who inspects you.
My uncle was in the fighter pilot training program many years ago, and right before the last cut was made (he had already made it from 400 to 5), they had a final eye-test, he failed it; due to some "leftside shadow vision" or something. The doctor said he was okay for helos though, so he became a chopper pilot. He flew sikorsky S-61 for many years, mainly with Sqn 722- the danish SAR sqaudron.
Then, as many others, he finished his military career and started flying busses for SAS. But that just wasn't him, so he seeked back into the RDAF. When they then tested his eyes again (standard procedures), the doctor (of course not the same doctor) said he would've
never have let him flown choppers in the first place, with that eye dysfunction.

So my uncle has flown choppers for 17 years without really having the eyes for it!

I don't know about the rules for commercial pilots, but I don't think they're very strict, as long as your faults are corrected by glasses or contacts of course.