Certified Ophthalmic Assistant Practice Exam – Prep Guide & Practice Test

The keratometer is specifically designed to measure the curvature of the cornea's central part, making it the appropriate instrument for this task. It operates by projecting a series of illuminated rings onto the cornea and analyzing the reflection of these rings, allowing for precise measurement of the corneal shape. This data is crucial in various applications, including fitting contact lenses, pre-surgical assessments for procedures like LASIK, and diagnosing corneal conditions.

In contrast, other instruments have different purposes: the lensmeter is used to measure the prescription of lenses; the sphygmomanometer is designed for measuring blood pressure; and the retinoscope evaluates the refractive error of the eye rather than the cornea's curvature. Thus, the keratometer stands out as the correct choice for measuring corneal curvature.