LISTEN UP EVERYONE:
When I was 18-22 I wore my contact day and night. I would sleep with them in for about 1 month straight, then throw them away. I wouldn't take them out to clean them, just put drops in every morning. This was for about 4 years.
I went to get an eye exam when I was 23 and the doctor asked me if I was leaving my contacts in alot, I told him yes, and he said that there were blood vessels growing into my cornea or something. Damage that could never be undone. The eyes weren't getting enough oxygen, so they had to grow new blood vessels to try to keep up. So now he says that soon I may not be able to wear contacts anymore...
So TAKE THEM OUT AT NIGHT. You must let your eyes breathe! They need oxygen just like every other part of your body. For the love of god man, you don't want to be 40 years old and wearing coke-bottle glasses.
Paul