What does a tonometer measure?

A tonometer is a medical device specifically designed to measure intraocular pressure (IOP) within the eye. This measurement is crucial for the diagnosis and management of conditions such as glaucoma, where elevated pressure can lead to damage of the optic nerve and loss of vision. By determining the pressure inside the eye, healthcare providers can assess the risk of developing glaucoma and other ocular disorders.

Intraocular pressure is a key indicator of eye health, and tonometry can be performed using various methods, including applanation tonometry and non-contact tonometry, often referred to as "air puff" tests. Monitoring this pressure is essential in ensuring that appropriate and timely interventions can be implemented if abnormalities are found.

The other options pertain to different aspects of health and do not relate to the function of a tonometer. For example, joint flexibility would typically be assessed by physical examination or flexibility tests, body temperature is measured using thermometers, and blood glucose levels are checked with glucose meters.