Tear film – Layers and formation
Tear film is composed of 3 layers. They are:
- Mucinous layer
- Innermost layer
- Mucin is secreted by conjunctival goblet cells and glands of Manz
- It transforms the corneal surface from hydrophobic to hydrophilic
- Aqueous layer
- Middle layer
- Secreted by the main and accessory lacrimal glands
- Lipid layer
- Outermost layer
- Secreted by meibomian glands
- Prevents evaporation of water
- Lubricates the eyelids
