Which equipment is commonly used to measure intraocular pressure?

The tonometer is the instrument primarily used to measure intraocular pressure (IOP), which is a crucial aspect of eye examinations, especially for glaucoma assessment. Monitoring IOP is essential because elevated pressure can lead to optic nerve damage and potential vision loss. Tonometers function by measuring the resistance of the cornea to an applied force, providing a reading that indicates the pressure within the eye.

In contrast, the lensometer is used to measure the prescription of lenses, the ophthalmoscope is utilized for inspecting the interior structures of the eye such as the retina and optic nerve, and the retinoscope helps to determine refractive errors by assessing how light is reflected from the retina. Each of these instruments serves distinct purposes in optometry, but none are specifically designed for measuring intraocular pressure, which solidifies the tonometer's role as the correct choice for this question.