Layers of Tears
Tears are not simply saline. They have a comparable structure to spit and contain proteins, lipids, metabolites and electrolytes. Each tear has three layers:
- An inward bodily fluid layer that keeps the entire tear attached to the eye.
- A watery center layer (the thickest layer) to keep the eye hydrated, repulse microorganisms and secure the cornea.
- An external sleek layer to keep the outside of the tear smooth for the eye to see through, and to keep different layers from vanishing.