noun (n)

• sharpness of vision; the visual ability to resolve fine detail (usually measured by a Snellen chart)(noun.cognition)

  Synonym:
  sharp-sightedness, visual acuity
  

  source: wordnet30
• a quick and penetrating intelligence(noun.cognition)

  Synonym:
  acuteness, keenness, sharpness
  

  source: wordnet30
• Sharpness or acuteness, as of a needle, wit, etc.(noun)

  source: webster1913