Eye Movement Terminology

Hi

this short video is to introduce terminology of eye movements. These are in 3 groups, ductions, versions and vergences.

DUCTIONS

First we will consider movements of a single eye alone, or Ductions.
We will face a patient with the eyes pointing straight ahead, this is called the primary position.
Now we cover or occlude the patients left eye, to observe ductions of the right eye.
movement of the cornea away from the midline is abduction, movement towards the midline is adduction.
movement upwards is supraduction or elevation and downwards is infraduction or depression.
rotation of the upper cornea towards the midline is incyclotorsion or intorsion, and rotation away is excyclotorsion or extorsion.

VERSIONS
Next we have conjugate eye movements in different directions of gaze. These gaze movements are termed versions.
Dextroversion is gaze to the right. The right eye is abducted and the left is adducted.
Laevoversion is gaze to the left. The right eye is now adducted with the left abducted.
upgaze and downgaze are supraversion and infraversion, although the terms upgaze and downgaze are also used.
Finally there is dextrocycloversion where the upper corneas move to the right and laevocycloversion where they move to the left.

VERGENCES
Finally we come to Vergences, here we have convergence, with both eyes adducted, and divergence where both eyes abduct back to the primary position.
There is also incyclovergence and excyclovergence.

So isolated movements of a single eye are descibed as ductions
Conjugate gaze movements of both eyes are versions.
Vergence movements are mirror image movements, being equal and opposite.
Both version and vergence movements can be described as combinations of ductions of the two eyes.