What instrument measures the curvature of the central part of the cornea?

The keratometer is the instrument designed specifically to measure the curvature of the central part of the cornea. This is crucial for assessing conditions related to the cornea, such as astigmatism and for planning surgical procedures like cataract surgery or corneal transplants. The keratometer provides readings that help eye care professionals determine the radius of curvature, which is significant for selecting appropriate contact lenses and ensuring the health of the cornea.

In contrast, other instruments mentioned do not serve this specific function. A tonometer measures intraocular pressure, which is important for diagnosing and managing glaucoma but does not assess corneal curvature. A keratoscope, while also related to corneal assessment, typically provides a broader view and is used to analyze the surface irregularities of the cornea rather than provide precise curvature measurements. A refractometer is used to determine the refractive index of lenses and liquids, which is essential for analyzing vision correction but does not measure corneal curvature.