Certified Ophthalmic Technician (COT) Test 2025 – 400 Free Practice Questions to Pass the Exam

The optimal choice for correcting corneal astigmatism involves understanding the specific characteristics of the lenses that target the irregular curvature of the cornea. Spherical Rigid Gas Permeable (RGP) lenses and soft lenses can effectively correct astigmatism by providing a smooth optical surface that conforms to the eye's shape. Spherical RGP lenses achieve this by utilizing their rigidity to maintain a consistent shape, allowing for effective light refraction despite the irregularities on the cornea.

When it comes to soft lenses, they can be designed with toric surfaces, allowing them to adapt to the astigmatic shape of the cornea while still providing comfort and adequate vision correction. Both types of lenses can significantly improve visual acuity for patients suffering from corneal astigmatism.

The other options do not directly address the nuances of corneal astigmatism as effectively. Cylinder lenses specifically refer to lenses designed for astigmatic correction, but this term is generally more relevant when discussing prescription parameters rather than the physical characteristics of the lens types. Bifocal lenses are primarily used for presbyopia, which involves a different refractive error and does not rectify astigmatism directly. Rigid Gas Permeable lenses alone can