What is the Tear Film?
When you blink, a film of tears spreads over the eye, making the surface of the eye smooth and clear. Without this tear film, good vision is not possible. The tear film consists of three layers, each with its own purpose:
- An Oily Layer
- A Watery Layer
- A Mucus Layer
The oily layer, produced by the meibomian glands in the eyelids, forms the outermost surface of the tear film. Its main purpose is to smooth the tear surface and reduce evaporation of tears.
The middle watery layer makes up most of what we ordinarily think of as tears. This layer, produced by the lacrimal glands in the eyelids, cleanses the eye and washes away foreign particles or irritants.
The inner layer consists of mucus produced by the conjunctiva. Mucus allows the watery layer to spread evenly over the surface of the eye and helps the eye remain moist. Without mucus, tears would not stick to the eye.
Video Title : Tear Film