What does the term "convergence" refer to in visual focus?

Convergence refers to the coordinated movement of both eyes inward toward the nose to focus on a nearby object or stimulus. This action helps to create a single image from the two slightly different perspectives provided by each eye, allowing for accurate depth perception and clarity of vision at close range. When we focus on something that is close, the eyes work together to align themselves so that the visual input from both eyes corresponds to the same object, resulting in a clearer view.

In contrast, the first option pertains to distance vision, which involves different mechanisms of focus, while the second option describes the opposite movement, known as divergence, where the eyes move outward. The fourth option refers to a visual issue where the ability to focus on close objects is impaired, which does not align with the definition of convergence. Thus, convergence specifically describes the inward movement of the eyes to maintain clarity and focus on nearby stimuli.