Certified Paraoptometric (CPO) Practice Exam 2025

What is the central area of a lens that provides optical correction?

1. Optical Zone

2. Center Thickness

3. Lens Core

4. Correction Zone

The correct answer is: Optical Zone

The central area of a lens that provides optical correction is known as the Optical Zone. This part of the lens is specifically designed to ensure that the light rays passing through it are focused accurately onto the retina, thereby correcting vision effectively. The Optical Zone is typically the area where the lens curvature is optimized to achieve the desired refractive power, making it crucial for vision clarity. While Center Thickness refers to the actual thickness of the lens at its center, it does not directly relate to the area responsible for optical correction. Lens Core is not a standard term used in optics to describe any specific functional area of a lens. Correction Zone might seem intuitive, but it is not the established term used in the field. Therefore, the Optical Zone is clearly the appropriate term for identifying the part of the lens focused on correcting vision.