What is a characteristic of plus lenses?

The correct answer highlights a unique property of plus lenses, which are used primarily for the correction of hyperopia (farsightedness). When plus lenses are rotated, crossed lines viewed through them exhibit a scissor-like movement due to the way they refract light. This phenomenon arises from the curvature of the plus lenses, which causes light rays to converge and can create visual effects that differ based on the lens orientation.

This rotating behavior is particularly significant during lens fitting and can help in determining the correct axis for cylindrical lenses if they are incorporated. Understanding this characteristic is essential for an optician as it relates to how lenses interact with visual stimuli, which is important when optimizing a patient's vision.

In contrast, other options do not accurately represent the defining features of plus lenses. For instance, while they do have an impact on the perception of straight lines and object sizes, the fluid and dynamic response to orientation changes is the distinctive factor, making the scissor movement a key characteristic of plus lenses. Additionally, plus lenses are not exclusive to correcting myopia; they are designed primarily for hyperopia.