**3. Types of corneal vascularization**

**Superficial**: In superificial corneal vascularization, vessels arrange in arborizing pattern in subepithelial layer and can be traced with conjunctival vessels. This type of vascularization may be observed in trachoma, and phlyctenular conjunctivitis.

**Deep**: In deep corneal vascularization, vessels are derived from anterior ciliary artery and lie in corneal stroma. Vessels are usually straight and not anastomosing. This type of vascularization may be observed in graft rejection, interstitial keratitis, deep corneal ulcer, and chemical burn.

**Pannus**: In pannus, extensive superficial vascularization occurs with cellular infiltration. It is of two types:

