The Three Layers of the Tear Film and Their Importance
Each time you blink, tears are spread across the surface of the eye. Your tear film has three layers: an oil (lipid layer), a aqueous layer, and a mucin layer.
The outer layer. This layer reduces evaporation of the tears.
The middle layer. This layer lubricates the eye and washes away debri.
The inner layer. This layer allows the tears to spread evenly across the surface of the eye and helps the tears stay in place.
When one or more of the layers of the tear film are not functioning correctly you may experience symptoms of dry eye.