Q: What percentage of patients in ICU develops some sort of ocular surface disorders?

Answer:  60% 

Patients in ICU develops impaired ocular defence mechanisms as a result of use of sedatives, neuromuscular blockades, multiorgan failures, positive pressure ventilation and various other reasons. Unfortunately, it does not get emphasis enough in teaching of Critical Care Medicine at bedside, and required ophthalmology consults frequently go ignored. Moisture chambers are said to be significantly better method than lubrication at preventing exposure keratopathy in ICU.

References:

Grixti A, Sadri M, Edgar J, Datta AV. Common ocular surface disorders in patients in intensive care units. The Ocular Surface. 2012;10:26–42