Dry Eyes & Your Tear Film
Dry eyes predominantly affects the stability your tear film. Your tear film is responsible for providing your eyes with the hydration and comfort you need to enjoy your vision. However, some conditions can affect your tear film’s integrity, causing to dry eye disease.
There are 2 common types of dry eye you can experience: aqueous tear deficiency (which is the lack of quality tears) or evaporative dry eye (which is a lack of lipids preventing evaporation).
The tear film is made of 3 distinct layers:
Mucus is the innermost layer of a person’s tear film. It helps the rest of the film adhere to the eye’s surface and spread evenly across it. Goblet cells, conjunctival epithelial cells, and, to a lesser extent, lacrimal glands, all help produce this layer.
Sandwiched between the mucus and lipid layer is water, scientifically known as the aqueous layer. Water is essential for keeping your eyes hydrated while also washing away foreign particles on the surface of your eye. The lacrimal glands are responsible for producing this layer and are located just above your eyelid area.
Lipids, or oils, make up the outermost layer of the tear film. They help seal in the rest of the layers and prevent them from evaporating. This layer is produced by meibomian glands located around the edges of your eyelid. Still, some medical conditions prevent the production of a stable lipid layer, leading to dry eye disease.