What does visual acuity measure?

Visual acuity measures the sharpness or clarity of vision. This metric indicates how well an individual can see fine details at a specific distance, typically assessed through an eye chart during an eye examination. For instance, the Snellen chart is commonly used to evaluate visual acuity by asking patients to read letters of varying sizes, which helps in identifying vision problems and determining the need for corrective lenses.

While color perception, field of vision, and depth perception are important aspects of visual function, they are not what visual acuity specifically measures. Color perception refers to the ability to distinguish different colors, field of vision assesses the extent of what can be seen peripherally while looking straight ahead, and depth perception involves understanding the relative distance of objects in three-dimensional space. Visual acuity focuses solely on how clearly one can see.