Anatomical Considerations
Potentially Adverse Effects

Corneal Vascularization
The invasion of blood vessels into the cornea is known as corneal vascularization. It may occur as the result of epithelial infection, degenerations, exposure to toxins, noninfectious inflammatory conditions, hypoxia, or trauma. In addition, vascularization may be induced by contact lens wear in the following circumstances:

The extent of vascularization is measured according to number of vessels which have invaded the cornea. In grade +1, only a small number of vessels are noted in the corneal periphery and are ingrown no more than 2 mm from the limbal area. In grade +4, the vessels come in from all directions and begin to cover the geometric center of the cornea.