1. Having keen eyesight; quick to notice visual details
   "The keen-sighted ranger spotted the bird a mile away";
   - Argus-eyed, hawk-eyed, lynx-eyed, quick-sighted, sharp-eyed, sharp-sighted, eagle-eyed
    
2. Capable of seeing to a great distance
   "the keen-sighted driver saw the car from miles away";
   - farseeing, farsighted

See also: presbyopic, sighted