What condition often requires special consideration when fitting contact lenses?

Keratoconus is a condition that significantly alters the shape and thickness of the cornea, leading to a bulging or cone-like appearance. This irregular corneal shape causes varying refractive errors, which often cannot be corrected effectively with standard spherical contact lenses. As a result, individuals with keratoconus may experience significant vision challenges, including distorted or blurred vision.

When fitting contact lenses for patients with keratoconus, practitioners typically need to consider the use of specialized lenses, such as rigid gas permeable (RGP) lenses or custom-designed scleral lenses. These lenses provide better support and stability over the irregular cornea, improving visual acuity and comfort. The fitting process may require additional measurements and evaluations to ensure the lenses align properly with the unique contour of the cornea.

In contrast, myopia, hyperopia, and astigmatism can often be corrected with standard soft lenses or standard toric lenses, making the fitting process less complex. While these refractive errors still require careful consideration during the fitting process, they do not present the same level of challenge as keratoconus, where the irregularity of the cornea necessitates specialized approaches.