It depends on your contacts and also on your eyes. With hard contacts, it's possible to get a much better fit, but they're also more sensitive to dust (that is, a speck of dust that really wouldn't bother you if you had soft contacts, will feel like a splinter of glass if you have hard contacts). I really rely on eye protection -- it's hard to ride without it. I've done it sometimes at night when I don't have clear lenses with me, and I can get away with it on a day when it's not too dusty, but when it's been dry and the cars are kicking up dust, it's hard Winter can be tough this way, too, if you have road salt and sand -- it accumulates on the road margins and gets blown around by cars and wind.