Fake Oakleys can't often make the same promises that the authentic ones can, so a piece of flying debris that might not have made it through an Oakley lens and into your eye could make it through a knockoff pair's lens.
As long as you know what you're buying and the seller is honest about whether his or her merchandise is authentic or not, purchasing fake, replica, or knockoff Oakley sunglasses can be a pleasant experience.
You may see them referred to as imitation Oakleys, Faux-kleys, knockoff Oakleys, replica Oakleys, and so on, but the bottom line is this: They are designed to look like the more expensive Oakleys out there.
While it is unlikely that a major watch manufacturer will pursue an individual for buying a counterfeit watch, knowingly buying a fake watch perpetuates the problem of knockoff and counterfeit watches.
If you still can't stomach the price of designer sunglasses even though you love their style and realize there is usually a warranty attached, you can always go for a knockoff pair.