I have been wearing contacts for about 25 years, and wore them 24/7 for about 15 years of that time. Basically I always made excuses and failed to take them out before bed for one reason or another. Since I am nearly legally blind and didn’t own any glasses for much of that time, it became a poor health habit that was very hard to break.
During that time I had to deal with several pink eye infections and also developed a mild case of GPC (giant papillary conjunctivitis.) This meant I couldn’t wear them at all – doctor’s orders. I was fortunate that all of these infections cleared up in time, with no permanent effect on my vision. Bad habits are tough to break though, and eventually I returned to wearing them 24/7.
The only reason I was able to stop is that my doctor basically gave me an ultimatum. My eyes had continued to get progressively more bloodshot and during a routine eye exam for a new script she told me that because I had deprived my eyes of oxygen for so long, I had grown permanent blood vessels along the surface of my cornea. She also said that eventually these vessels would alter the shape of my eye, making it impossible to ever wear contacts again.
It’s been a few years since then, and I’m happy to say I hardly ever wear them to bed anymore. If I do I definitely feel the pressure @sevenfourteen described above, and it’s pretty excrutiating. There’s nothing worse than the feeling of a contact adhered to your eyeball, and having to peel it off. ugh!
Since your eyes are already at a higher risk for developing an infection due to your long wearing schedule you might want to check with your doctor about possibly switching to a contact lense that has a more permeable surface. I have found Acuvue Oasys to be very comfortable.