Yeah if you get contacts wet don't they like swell up?
I dove into a swimming baths with my GLASSES on
But yes indeed, you're not supposed to immerse them in tap water or in swimmingpool water. It's nothing to do with swelling up, it's because masses of bacteria and chemicals which congregate on them, and can't be blinked away as they normally would because the lens is on your eyeball.
- Bacterial infection and calcification/fluoridation of the cornea were the reasons that huge hullaballoo came over about people going blind. They used tap water, which isn't 100% pure water, and it's been treated with so many chemicals.
You have to keep them soaked in a special saline solution when they're not in your eyes. This keeps them bacteria-free and moist. In your eye, your eye's own defences keep them clean and moist.
If you're in really baking heat in a really dry atmosphere, it can get a bit stingy if your eyes dry out, but contact lenses make you utterly invincible in a stare-out competition
Most contacts, you're not supposed to sleep with them in. Not sure why that is. I can close my eyes, and I don't feel their presence. I don't imagine I would in my sleep either...