What test measures the sharpness of vision?

The visual acuity test is specifically designed to measure the sharpness or clarity of vision, which reflects the ability of the eye to discern fine details. It typically involves reading letters on a standardized chart from a specified distance to determine the smallest letters that can be seen clearly. The result gives a clear indication of the individual's eyesight and is crucial for diagnosing any refractive errors or potential vision problems.

The other tests listed have different purposes. The refraction test assesses how light is focused by the eye and helps determine the appropriate prescription for corrective lenses, but it does not measure vision sharpness directly. The color perception test evaluates the ability to distinguish colors and is not related to visual acuity. Finally, the visual field test examines the full horizontal and vertical range of vision, identifying any blind spots, rather than measuring how sharp vision is. Thus, the visual acuity test is the appropriate choice for assessing sharpness of vision.