Tears keep your eyes wet and smooth and help focus light so you can see clearly. They also protect your eyes from infections and irritants.
Every time you blink, a thin layer of tears called a “tear film” spreads across the surface of your cornea. Tears come from glands above your eyes then drain into your tear ducts and down through your nose.
What are tears made of?
Tear film has 3 different layers:
- The oily outer layer keeps tears from drying up too quickly and makes the surface of the eyes smooth
- The watery middle layer keeps the eyes wet and nourishes the eye tissue
- The inner mucus layer helps the tear film stick to the surface of the eyes
As you age, the ability to produce the oily outer layer decreases which may result in dry eye.