#sight.optical_instrument  a optical instrument for aiding the eye in aiming, as on a firearm or surveying instrument
  supertype:  optical_instrument__opticalinstrument  an instrument designed to aid vision
  subtype:  bombsight  gunsight
  part:  eyepiece
  part of:  firearm__piece__small-arm__smallarm  a portable gun; "he wore his firearm in a shoulder holster"
  part of:  surveying_instrument__surveyinginstrument__surveyor's_instrument  an instrument used by surveyors

No statement uses or specializes sight.optical_instrument; click here to add one.