@umbra21 - It's actually surprising how uncomfortable dry eyes can be, I find. When I was younger and spent a lot of time on airplanes I found this to be a problem, I guess because of lack of sleep combined with the recycled air in an aircraft and even in airports.
My eyes would actually become quite painful, I guess from irritation from blinking without enough of a tear film to protect them. They are really delicate and people are lucky that they don't have more problems with their eyes.
I found that using eye drops was the best solution for the problem, although I was happy to stop spending so much time in airports. I was very lucky never to get a serious infection but I could certainly see how it could happen.