Certified Paraoptometric (CPO) Practice Exam 2025

Which lenses have the same power across all areas to treat either myopia or hyperopia?

1. Aspheric lenses

2. Spherical lenses

3. Spherocylindrical lenses

4. Trifocal lenses

The correct answer is: Spherical lenses

Spherical lenses have the same curvature across their entire surface, which ensures a uniform optical power. This characteristic allows them to effectively focus light for individuals suffering from either myopia (nearsightedness) or hyperopia (farsightedness). Because they provide a consistent focal point regardless of the viewing angle, they are a straightforward option for corrective vision. Aspheric lenses, on the other hand, are designed with varying curvature and can provide better visual acuity for specific conditions, but they do not provide uniform power. Spherocylindrical lenses incorporate both spherical and cylindrical components, making them suitable for astigmatism but not for uniform power across all areas like spherical lenses. Trifocal lenses are multifocal and offer different powers for near, intermediate, and distance vision, which does not align with the requirement for a consistent power across all zones.