What Is Dry Eye?
Dry eyes can occur in 2 ways: lack of tears (evaporative dry eye) and lack of quality tears (aqueous tear deficiency). Both of these issues impact your tear film, a tear layer on the surface of your eyes responsible for keeping them comfortable.
There are 3 different layers to your tear film, and each layer has its unique role to play in your eye comfort. These layers include:
The Mucus Layer
The innermost layer of your tear film, the mucous layer, is responsible for spreading your tears evenly across the surface of your eye.
The Aqueous Layer
The aqueous layer is the watery middle layer of your tear film. Produced by your lacrimal glands, this layer is responsible for keeping your eyes hydrated and comfortable.
The Lipid Layer
The lipid layer is the outermost oily layer of your tear film. These oils are produced by meibomian glands in the margins of your eyelids and are responsible for “sealing in” the other layers of your tear film, preventing them from evaporating.