For a patient with exophthalmic eyes needing a toric lens, which of the following is a concern?

When dealing with a patient who has exophthalmic eyes requiring a toric lens, the concerns primarily lie in how the specific eye condition interacts with the properties and characteristics of contact lenses.

The aspect of lens stability is crucial because exophthalmic eyes often have a different anatomical configuration. The positioning of the eyelids and the anatomical changes associated with protruding eyes can lead to insufficient lid forces, which are essential for maintaining the stability of a toric lens. Toric lenses are designed to correct astigmatism and must remain in a specific orientation to function effectively. Without adequate lid interaction, these lenses might not stabilize as they should, leading to issues such as rotation and discomfort.

Additionally, the dehydration of the lens is another significant consideration. In exophthalmia, the exposure of the cornea can be increased, leading to a higher rate of evaporation of the tear film and, potentially, excessive dehydration of the lens material. Dehydrated lenses can become uncomfortable, affect vision clarity, and impact lens performance due to changes in their optical properties.

Thus, both the concerns about excessive dehydration and the difficulty in maintaining lens stability, due to the anatomical changes in exophthalmic eyes, underscore the challenges posed when fitting toric lenses in