Across the margin of the eyelids (the edges that touch when you close your eyes) lie some tiny oil glands, which are called the meibomian glands.You have about 31 meibomian glands in the top eyelid, and 31 in the lower lid.These glands perform an essential function in the eyelids and for the eyes. They secrete oil that coats the surface of the eye, thus preventing the watery tear layer from drying out and evaporating. Aside from this, the meibomian glands help to keep the ocular surface of the eyes clean and well lubricated at all times. The watery component in the tears, a mucus layer, and the oil secreted by the meibomian glands together makes the tear film.
These three layers of the tear film help to lubricate the eyes and keep it healthy. They’re also responsible for maintaining our vision. If anything goes wrong with this special component of our eyes, we might suffer from eye irritation or even worse, blurred vision.