The cornea is the clear, protective layer at the front of your eye. It helps shield your eye from dust and germs while also playing a key role in focusing light so you can see clearly. Kept moist and healthy by your tears, the cornea is essential for sharp vision (1).

Infections such as Bacterial Conjunctivitis and Viral Conjunctivitis can affect the cornea.

The innermost layer, closest to the eye’s surface, is the mucus layer. It contains mucins produced by goblet cells in the conjunctiva. This layer ensures that the watery layer spreads evenly over the eye’s surface by converting the hydrophobic (water-repelling) surface of the cornea into a hydrophilic (water-attracting) one, promoting uniform tear distribution (2).

A compromised mucus layer may contribute to Dry Eye.

Situated beneath the lipid layer, the aqueous layer is the thickest of the three. It is primarily composed of water and is produced by the lacrimal glands located above each eye. This layer hydrates the eye, supplies essential nutrients to the cornea, and helps flush away debris or foreign particles (2).

An imbalance in this layer can be associated with Dry Eye (3).

This is the outermost layer of the tear film. It consists of oils produced by the meibomian glands, which are located along the edges of the eyelids. The primary function of the lipid layer is to prevent the evaporation of tears by reducing surface tension, thereby keeping the underlying layers stable and the eye surface smooth. (2)

Dysfunction in this layer can lead to Meibomian Gland Dysfunction (MGD), contributing to Dry Eye.