Acuity has to do with sharpness and smartness. Do you always get A's in math? Then you have an acuity for numbers.

People often talk about "mental acuity," which is a fancy way of saying intelligence, brains, or smartness. There are specific kinds of acuity, too. As people become very old, they tend to lose their acuity in many areas, including their vision, which is one reason very old people don't drive as well. A 40-year-old quarterback isn't going to have the same acuity for seeing receivers and throwing the ball as a 25-year-old quarterback.

Definitions of acuity

n sharpness of vision; the visual ability to resolve fine detail (usually measured by a Snellen chart)

sharp-sightedness, visual acuity
20/20, twenty-twenty
normal visual acuity, as measured by the ability to read charts at a distance of 20 feet
unusually acute vision
Type of:
sight, vision, visual modality, visual sense
the ability to see; the visual faculty

n a quick and penetrating intelligence

acuteness, keenness, sharpness
steel trap
an acute intelligence (an analogy based on the well-known sharpness of steel traps)
Type of:
the ability to comprehend; to understand and profit from experience