The cornea is the clear transparent part of the eye. It is made of epithelial tissue that covers the cornea and acts as a barrier. It is composed of five layers from front to the back andt has rich nerve supply. There is a tear film covering the surface of the cornea that has 3 layers viz. the oil or lipid layer, the water or lachrymal layer, and the mucus or mucin layer. This forms a protective barrier on the cornea. Corneal ulcers are injuries to the epithelial covering with infection and inflammation due to various microorganisms, fungi, or acanthamoeba.