Our eyes need tears to stay healthy and comfortable. Every time we blink, a film of tears coats the surface of the eye, which helps to keep it clean and clear. Dry eye occurs when your eyes don't make enough tears to stay moist, or the tears that you make aren't working correctly. If you have severely dry eyes, it is important to get treatment — since letting it go could cause damage to the cornea (the clear outer layer in the front of the eye).