The human cornea is composed of three layers, the outer or epithelial layer, the middle or stromal layer, and the inner or endothelial layer. The endothelial layer is composed of a single layer of thousands of small cells. These endothelial cells are responsible for pumping fluid out of the cornea so it can remain clear and thin and provide good vision for the eye. When the cells become dysfunctional, damaged, or destroyed, the corneal fills up with fluid and becomes swollen and cloudy, causing blurry vision making it necessary to consider Corneal Transplantation when no other less invasive options such as wearing glasses or being fit with contact lenses are available.

A normal lens is clear. It lets light pass to the back of the eye and helps with focussing. A cataract is a cloudy area in the lens inside the eye, which blocks some of the light. As a cataract develops, it becomes harder for a person to see.

Glaucoma is a leading cause of blindness in the U.S. It occurs when the pressure inside the eye rises, damaging the optic nerve and causing vision loss. Some cases have normal or near normal eye pressures.  The condition often develops over many years without causing pain or other noticeable symptoms – so you may not experience vision loss until the disease has progressed.