Certified Paraoptometric (CPO) Practice Exam 2025

What type of letters are most often used to measure distance acuity?

1. Keratometry

2. Floaters

3. Snellen

4. Flashes

The correct answer is: Snellen

The correct answer is indeed Snellen letters. These letters are commonly used in vision tests to measure an individual's distance acuity. The Snellen chart, which features large letters at the top becoming progressively smaller toward the bottom, allows eye care professionals to assess how well a person can see at various distances. The letters typically consist of a standardized format of letters that are specifically designed to ensure consistent measurement across different tests and settings. Keratometry refers to the measurement of the curvature of the cornea, not distance acuity, while floaters are visual phenomena that can occur in the eye, and flashes refer to brief bursts of light. Both floaters and flashes do not pertain to measuring visual acuity and are more related to symptoms that patients may report regarding their vision.