Certified Paraoptometric (CPO) Practice Exam 2025

What is a common characteristic of minus lenses?

1. They magnify objects

2. They minify objects

3. They are used exclusively for reading

4. They cannot be combined with prism

The correct answer is: They minify objects

Minus lenses are indeed characterized by their ability to minify objects. This happens because they diverge light rays as they pass through the lens, which causes the images to appear smaller than they do to the naked eye. This optical behavior is particularly useful for individuals who are nearsighted (myopic), as it helps them see distant objects more clearly while effectively reducing the size of those images. The other options suggest abilities or characteristics that do not apply to minus lenses. For instance, minus lenses do not magnify objects; this function is associated with plus lenses, which are used to help with conditions such as farsightedness. Additionally, while minus lenses can be used for reading, they are not exclusively for that purpose; they are primarily designed to assist with distance vision. Combining lenses with prism is also possible, and in many cases, minus lenses can indeed be paired with prism adjustments to further correct vision issues.