In the case of observed corneal edema inferiorly under a prism ballast toric soft lens, what is the probable cause?

One possible cause of observed corneal edema inferiorly under a prism ballast toric soft lens is that the prism thickness is too great. In toric soft lenses with prism ballast, the thicker part of the lens is designed to keep the lens oriented correctly on the eye. However, if the prism thickness is excessive, it can lead to insufficient oxygen transmission to the cornea, particularly in the area beneath the ballast.

The cornea relies on a regular supply of oxygen to maintain its health and integrity, and when the oxygen demand exceeds the cornea's supply due to the thick prism area of the lens, this imbalance can result in corneal edema. Edema is characterized by swelling or fluid accumulation within the corneal tissue, often visible as haziness or cloudiness.

This situation highlights the importance of proper lens fitting and prescription to ensure optimal oxygen supply to the cornea, which is crucial for maintaining clear vision and overall ocular health.