What does visual acuity refer to?

Visual acuity refers specifically to the clarity or sharpness of vision and is a measure of the eye's ability to perceive and comprehend visual information, which includes interpreting light rays. It essentially reflects how well a person can see fine details, typically assessed using an eye chart during an eye examination. High visual acuity means that the person can see clearly at various distances, while reduced visual acuity indicates a potential issue with vision that may require correction.

The other options relate to aspects of vision, such as color perception and night vision, but do not specifically define visual acuity. Recognizing faces is a complex cognitive process that relies on visual acuity but is not a direct definition of it.