squint (non-paralytic)

Last reviewed 03/2023

The features of a non-paralytic, or concomitant, squint include:

  • usually congenital
  • diplopia is absent
  • extraocular muscles and nerves are grossly normal
  • the angle between the longitudinal axes of the eyes remains constant on testing eye movements
  • both eyes have full movement if tested separately

There is excess tone in one muscle compared with its antagonist resulting in deviation of the eye.