Visual acuity is defined as the ability to:

Visual acuity primarily refers to the ability to perceive and comprehend fine details and resolve visual images clearly. It is a measure of how well the eye can distinguish two points that are close together, which is essential for tasks such as reading, driving, and recognizing faces.

This definition aligns with the concept of perceiving and comprehending light rays, as visual acuity is fundamentally about the eye's ability to interpret the light reflected from objects into a clear and detailed image.

Focusing on distant objects only, resolving colors in dim lighting, and detecting motion at high speed relate to specific aspects of vision but do not capture the overall definition of visual acuity, which emphasizes clarity and detail rather than just distance, color, or motion.