acuity acuity /əˈkjuːɪti/

noun

1. A quick and penetrating intelligence  ( acuity , acuteness , keenness , sharpness )
   a quick and penetrating intelligence
    He argued with great acuteness
   he argued with great acuteness
    I admired the keenness of his mind
   I admired the keenness of his mind
   
2. Sharpness of vision; the visual ability to resolve fine detail (usually measured by a Snellen chart)  ( acuity , sharp-sightedness , visual acuity )
   sharpness of vision; the visual ability to resolve fine detail (usually measured by a Snellen chart)