Certified Paraoptometric (CPO) Practice Exam 2025

The primary function of cycloplegic drugs is to dilate the pupil and prevent accommodation. These medications temporarily paralyze the ciliary muscle, which is responsible for focusing (accommodation). By doing this, cycloplegics not only cause the pupil to enlarge but also inhibit the eye's ability to change focus from near to far, and vice versa. This is particularly useful in ocular examinations, allowing for a more effective evaluation of the retina and other internal structures without the interference of focusing changes during the procedure.

While pupil constriction is achieved with other types of medications, it is not a function of cycloplegic drugs. Numbing the surrounding area is the role of anesthetic agents, not cycloplegics. Staining the cornea is typically performed using dyes like fluorescein during certain tests, which is unrelated to the function of cycloplegic medications.