Ocusan Single Dose Eye Drops Ocusan is a sterile, preservative-free, viscoelastic clear corneal shield. It consists of natural, biological substances. Ocusan protects, moisturizes and viscosifies the eye surface. Relief of dry eye symptoms caused by: Keratoconjunctivitis sicca. Corneal damage, erosions, surgical corneal interventions. Contact lenses. Hormone dysbalance (menopause). Air condition, wind, cold, dry heat, dust, smoke, pollution. Computer work, long drives, long-distance flights. Swimming in cloride-containing water.