Certified Paraoptometric (CPO) Practice Exam 2025

Which type of lens provides multiple powers to be used at different distances?

1. Single vision lenses

2. Trifocal lenses

3. Multi-focal lenses

4. Aspheric lenses

The correct answer is: Multi-focal lenses

Multi-focal lenses are designed to accommodate vision needs at varying distances. This type of lens includes multiple optical powers within a single lens, allowing the wearer to see clearly both up close and at a distance. The design typically features segments or zones for close vision, intermediate vision, and distance vision, providing a seamless transition between these different focus areas. Single vision lenses, in contrast, provide only one optical power and are primarily designed for one specific distance. Aspheric lenses are designed to reduce distortion and improve clarity but do not inherently provide multiple viewing distances. Trifocal lenses do offer three distinct areas for viewing, but they are a specific category within multi-focal lenses, which encompass a broader range of designs, including progressives that provide an even smoother transition between power zones. Thus, multi-focal lenses represent a more inclusive and versatile solution for those with varying vision correction needs.