Certified Paraoptometric (CPO) Practice Exam 2025 – All-in-One Study Guide to Ensure Exam Success!

A Tonopen is indeed a handheld tool designed specifically for measuring intraocular pressure (IOP). This device is commonly used in optometric and ophthalmological practices to aid in the diagnosis of conditions such as glaucoma. The Tonopen is valued for its portability and ease of use, allowing practitioners to obtain accurate IOP readings with minimal discomfort to the patient. It functions by making gentle contact with the eye's surface and using sensitive pressure-sensing technology to provide precise measurements.

The other options pertain to different aspects of eye care. Visual acuity testing involves assessing how well a person can see, often using an eye chart, and is not related to measuring IOP. Eye drops are used for various therapeutic purposes, such as reducing eye pressure or treating infections, and are not measurement tools. Methods for determining visual fields involve testing the peripheral vision and are distinctly separate from intraocular pressure measurement.