It sounds like your eyes are very dry, have you tried using some tears?
I don't think it's the Asacol, but you may be generally dehydrated. Drink lots of water, see if it improves!
Hopefully it is something that simple.
49 year old female attorney, diagnosed UC/pancolitis 1985, no surgery but much suffering.
Asacol/5ASA 6x400 mg maintenance for 20+ years; use prednisone & Rowasa for flares.
August 2008 sought care of naturopathic doctor. Food sensitivity test showed wheat/gluten, other intolerances; eliminated all wheat/gluten from my diet. Probiotics (Ultimate Flora, 50 billion), trying Curamin. Doing OK, but still have some bad days.