What test measures intraocular pressure?

Tonometry is the test that specifically measures intraocular pressure (IOP), which is a critical aspect in diagnosing and managing conditions such as glaucoma. By assessing IOP, healthcare professionals can determine whether the pressure within the eye is at normal levels, elevated, or potentially harmful. This measure is essential for evaluating the risk of optic nerve damage and is a standard procedure during an eye examination.

The other options are related to different aspects of eye health: pachymetry measures corneal thickness, refraction assesses the eye's ability to focus light and is used to determine the prescription for glasses or contact lenses, while perimetry tests the visual field to check for blind spots and areas of lost vision. Each of these tests has its own specific purpose and is important for a comprehensive eye examination, but only tonometry is designed to directly assess intraocular pressure.