Contrast sensitivity in patients with keratoconjunctivitis sicca before and after artificial tear application.

Poor stability of the precorneal tear film causes dry eye symptoms and has detrimental effects on the optical function of the eye. In 50 patients with dry eyes the local instillation of artificial tears significantly improved contrast sensitivity (P < 0.001), using the Vision Contrast Test System 6500. In the untreated eyes no significant changes were found to occur (P = 0.56).