Illinois Vision Certification Practice Test

What term refers to the adjustment of the lens size for light focusing?

1. Accommodation

2. Adaptation

3. Adjustment

4. Refraction

The correct answer is: Accommodation

The term that describes the adjustment of the lens size for light focusing is "Accommodation." This is a crucial process performed by the eye that allows the lens to change shape to focus on objects at various distances. When you look at something close up, the eye muscles contract, causing the lens to become thicker and more rounded, which increases its refractive power to help focus light onto the retina. Conversely, when looking at distant objects, the lens flattens. This dynamic adjustment is essential for clear vision across a range of distances. In contrast, adaptation generally refers to the eye's ability to adjust to different light conditions, such as moving from a dark environment to a bright one. Adjustment is a vague term that does not specifically relate to the focusing of light in the lens. Refraction is the bending of light as it passes through different mediums, which is an optical principle, but not specifically related to lens size adjustment within the eye.