I've been wearing contact lenses for 16 years and for the last 12 months have been wearing Bausch & Lomb Purevision lenses. Thes are a new type, 30 day extended wear, polymer lenses. I have to say they are fantastic, very comfortable in any condidion, on the ground, in an aircraft, presurised or not, offices etc.
I wear them 18 hrs a day, 7 days a week with no problems, or vascularisation(dialaton of the blood vessels in the white part of the eye).
Contrary to the makers claims, these 30 day lenses should be taken out each night unless you really need to sleep in them ocasionally which is ok. Continued extended wear is causing a much higher infection rate than previously thought.