What layer of the tear film serves as the oily layer?

The oily layer of the tear film is known as the lipid layer. This layer is crucial for maintaining the stability and integrity of the tear film by reducing evaporation. It acts as a protective barrier on the surface of the eye, preventing moisture loss and helping to keep the tear film well-distributed over the ocular surface. The lipid layer is produced by the meibomian glands located in the eyelids, and its composition primarily includes various lipids that contribute to the overall health of the tear film and the comfort of the eye. Understanding the role of the lipid layer is essential in the study of ocular health, as imbalances in this layer can contribute to dry eye symptoms and other visual disturbances.