Dry eye disease (keratoconjunctivitis sicca) is a very common condition. It affects one in five adults. For your eyes to be comfortable, you need an adequate supply of tears. When you don’t have enough tears to provide lubrication, or they dry too quickly (for example, riding a bike), dry eye will develop. You may experience dry eye when flying, after reading or looking at a computer screen, or being in an airconditioned room.