[n] a quick and penetrating intelligence; "he argued with great acuteness"; "I admired the keenness of his mind" [n] sharpness of vision; the visual ability to resolve fine detail (usually measured by a Snellen chart)
acuteness, keenness, sharpness, sharp-sightedness, visual acuity
acridity, acumen, acumination, acuteness, adroitness, agility, alertness, apperception, aptitude, aptness, astuteness, attention, attentiveness, braininess, brightness, brilliance, clear thinking, cleverness, cogency, dexterity, discernment, edge, esprit,