During an eye exam, which test is commonly used to assess the shape of the cornea?

The assessment of the shape of the cornea is primarily performed using keratometry. This test is specifically designed to measure the curvature of the anterior surface of the cornea, providing crucial data necessary for determining conditions related to the cornea, such as astigmatism. Keratometry involves the use of a keratometer, which focuses light on the cornea and analyzes the reflected light to calculate the curvature measurements. This information is essential for fitting contact lenses and planning refractive surgeries, making keratometry a vital part of eye examinations related to corneal health.

The other tests serve different purposes. For instance, the refraction test is used to determine a patient's prescription for glasses or contact lenses by assessing how light is focused in the eye, rather than measuring corneal shape. The pupil reflex test evaluates the response of the pupils to light and accommodation but does not provide information about the cornea's curvature. Tonometry is utilized to measure intraocular pressure to evaluate for glaucoma, which also does not involve assessing the shape of the cornea. Thus, keratometry is the only test listed that focuses specifically on the curvature and shape of the cornea.