I have had almost constant problems with my eyes for years. Blurred vision, itching, irritation, uveitis, floaters, eye pain, sensitivity to light, infections and also
several episodes of severe conjuctivitis that caused my eyes to swell shut for several days. Most worrying of all, after a week of pain, a small tear in the retina of one eye. I was referred as an emergency to an opthalmologist who said he knew of no connection at all between Crohn's and eye problems!! He had no suggestions as to how I might manage the problem, so I had to work it out myself, and now always keep an unopened bottle of antibac eye drops ready in the refrigerator for emergencies, plus bathe my eyes daily with saline solution.
Antihistamines are useful if eyes are itchy.
Drinking lots and lots of water every day (2 liters) also seems to help quite a lot, as I guess it keeps everything in the body including eyes lubricated.