I could stand in the middle of a dust storm with my eyes wide open and it wouldn't affect me one iota, nor would I even begin to feel the lenses in my eyes but the variety and brand of contacts makes a huge difference.
I have Frequency 55 lenses, they are not very "breathable" and therefore don't let dirt, dust, whatever in to irritate my eyes. But they also don't let oxygen or moisture in very well either.
My eye Dr. Is nagging me to try a more breathable lens now that I moved to an extremely dry area instead of living next to the ocean. I'm putting it off.... I absolutely love theses lenses and the fact I have no idea they are in (well except that I can actually SEE).
Oh and blind people pay more than $260 a year, WAY more actually but considering my last pair of glasses was $1300, I am ok with that, still cheaper than glasses since I need a new prescription every year.