Certified Paraoptometric (CPO) Practice Exam 2025

Which of the following describes an effect of a spherocylindrical lens?

1. It improves night vision

2. It corrects for single vision

3. It adjusts vision for varying meridians

4. It provides a slight magnification

The correct answer is: It adjusts vision for varying meridians

A spherocylindrical lens plays a crucial role in vision correction by addressing astigmatism, which is caused by the irregular shape of the cornea or lens in the eye. This type of lens contains both spherical and cylindrical components, allowing it to correct refractive errors in different meridians. The cylindrical part of the lens specifically compensates for the varying curvature of the eye, enabling sharper vision at varying angles and ensuring that light rays focus correctly on the retina regardless of the direction they enter the eye. This ability to correct for the distortion caused by different meridians highlights the significance of the spherocylindrical lens in providing a well-rounded vision correction solution especially for individuals with astigmatism. In contrast, the other options focus on effects that do not pertain directly to the primary function of a spherocylindrical lens. For instance, improving night vision and providing a slight magnification are benefits typically associated with other types of corrective lenses or specific conditions rather than the dual corrective function of a spherocylindrical lens. Similarly, correcting for single vision pertains generally to spherical lenses, which do not account for the variations in curvature that the cylindrical component of a spherocylind