Meibomian Gland Dysfunction (MGD) is a common eye condition, yet many people don't realize they have it. You get it when there's a problem with a few dozen tiny glands in your eyelids that help make tears.
These meibomian glands make an oil called meibum. Meibum, water, and mucus form the three layers of tear film, the fluid that keeps your eyes moist. The oil helps prevent the water layer on the eye surface from drying out.