Certified Paraoptometric (CPO) Practice Exam 2025

What is the term for the eye's ability to focus on objects at varying distances?

1. Refraction

2. Accommodation

3. Convergence

4. Adaptation

The correct answer is: Accommodation

The term that describes the eye's ability to focus on objects at varying distances is accommodation. This physiological process involves the eye changing the shape of the lens, allowing it to focus light rays correctly on the retina. When we look at something far away, the ciliary muscles relax, and the lens flattens. Conversely, when we look at close objects, the ciliary muscles contract, causing the lens to bulge and increase its curvature to focus the image effectively. Refraction refers to the bending of light as it passes through different media, which contributes to the overall focusing ability of the eye, but it does not describe the changing focus on varying distances. Convergence is the inward movement of the eyes towards each other when looking at close objects, which is a separate aspect of visual coordination. Adaptation typically refers to the eye's ability to adjust to changes in light levels. Thus, the correct answer, accommodation, specifically relates to the lens's ability to change shape to achieve clear vision at different distances.