Originally posted by: VanillaH
being a captain obvious here... but here is my plug : constant wear of contacts blocks off air from retina resulting in severe oxygen deprivation. my sister had it bad at one time and i was told she almost went blind from that. proabably a huge YMMV, but certainly not advisable to anyone
Exactly right.
When I was young and irresponsible, I left my contacts in for weeks at a time. I rationalized that I "just didn't have the time" to mess with cleaning and enzyming them (this was back when enzyming took 3-4 hours). My eyes would get severely dry. After a while, I would even get bad photophobia (sensitivity to light - my eyes actually *hurt* when the sun was out). Once it hurt so bad, I couldn't even drive.
I went to my eye doctor for a routine exam and she told me that I had corneal ulcers. Additionally, the blood vessels in my eyeball were starting to grow into the iris (the colored part of my eye) due to oxygen deprivation (because I kept the contacts in all the time, my eyes couldn't get enough oxygen). She wouldn't write me a new prescription until the ulcers healed a bit.
After that experience, I rarely let my contacts go more than the two weeks I was supposed to wear them, and I'd let my eyes take a literal "breather" at *least* one full day a week.
If I had kept being irresponsible with my contacts, the blood vessels would continue to grow into my iris until they pass in front of my pupil (the dark area in the middle)... which causes blindness. And the blood vessels don't turn around and retreat from the iris after you start taking care of your eyes... once they're there, they're there.
You've only got one pair of eyes. Don't take them for granted.