Duction


A duction is an eye movement involving only one eye. There are generally six possible movements depending upon the eye's axis of rotation:
  1. Abduction refers to the outward movement of an eye.
  2. Adduction refers to the inward movement of an eye
  3. Supraduction / sursumduction / elevation
  4. Infraduction / deorsumduction / depression
  5. Incycloduction / intorsion
  6. Excycloduction / extorsion

    Forced duction test

The forced duction test is performed in order to determine whether the absence of movement of the eye is due to a neurological disorder or a mechanical restriction.
The anesthetized conjunctiva is grasped with forceps and an attempt is made to move the eyeball in the direction where the movement is restricted. If a mechanical restriction is present, it will not be possible to induce a passive movement of the eyeball.