What is the primary use of tonometry in ocular health?

Tonometry is primarily used to measure intraocular pressure (IOP), which is crucial for assessing the risk of glaucoma, a condition that can lead to vision loss if left untreated. By measuring the pressure inside the eye, healthcare providers can identify if the IOP is within a normal range or if it exceeds the levels typically associated with glaucoma. This test helps in the early detection and management of eye diseases, allowing for timely interventions that can preserve vision.

In contrast, assessing refractive error involves determining how well the eye focuses light, which is unrelated to pressure readings. Checking for cataracts requires different diagnostic techniques, primarily visual acuity tests and examination of the lens, rather than tonometry. Evaluating retinal health typically involves imaging and examination methods, such as fundus photography or optical coherence tomography, rather than measuring intraocular pressure. Thus, the primary and most relevant function of tonometry in ocular health is indeed the measurement of intraocular pressure.