Certified Paraoptometric (CPO) Practice Exam 2025

What type of lenses are designed to correct vision at just one distance?

1. Multi-focal lenses

2. Single vision

3. Bifocal lenses

4. Trifocal lenses

The correct answer is: Single vision

Single vision lenses are designed specifically to correct vision at just one distance, whether that be for distance viewing or for near vision tasks such as reading. These lenses provide a uniform prescription across the entire lens surface, allowing the wearer to focus clearly at the chosen distance. Multi-focal lenses, on the other hand, incorporate multiple prescriptions within the same lens to assist with seeing at various distances, while bifocal lenses typically provide two distinct areas for near and far vision, and trifocal lenses offer three areas for near, intermediate, and far vision. Thus, while these other types of lenses serve specific purposes related to multiple vision distances, single vision lenses are solely focused on correcting one specific distance.