Certified Paraoptometric (CPO) Practice Exam 2025

What class of medication do miotics belong to?

1. Dilators

2. Constrictors

3. Antihistamines

4. Lubricants

The correct answer is: Constrictors

Miotics are classified as constrictors because they function to decrease the size of the pupil, or constrict the pupil, in the eye. These medications work primarily on the iris sphincter muscle, causing it to contract. This contraction leads to pupil constriction, which is the opposite effect of mydriatic drugs that dilate the pupil. Miotics are often used to treat conditions such as glaucoma, where reducing intraocular pressure is essential. Their mechanism of action helps in facilitating the outflow of aqueous humor from the eye, contributing to the lowering of intraocular pressure, which is critical for managing this condition. Understanding this function is crucial for those in optometric practice, as it aligns with patient treatment plans, especially in managing ocular conditions requiring careful pupil size regulation.