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tertiary position

A tertiary position is any oblique position of the eye, such as up and right or down and left. The primary position is straight ahead with the body and head erect, and the adducted, abducted, elevated and depressed positions are the secondary positions.1 Four oblique versions bring the eyes into the tertiary positions: dextroelevation, dextrodepression, levoelevation and levodepression.2

The eye reaches a tertiary position by rotating about an oblique axis in Listing's plane, which is equivalent to moving about the horizontal and vertical axes at the same time.2 The four tertiary positions join the primary and four secondary positions to make the nine diagnostic positions of gaze, where the deviation is measured to find which muscle is involved in a paralytic strabismus.3 Older texts call the eight secondary and tertiary positions the cardinal positions, yet in ocular motor physiology that term belongs only to the secondary positions reached by the cardinal movements.3

More detail

Listing's law holds for movements from the primary position into tertiary positions, so the eye arrives there without cyclorotation.1 Even so, an afterimage cross carried into a tertiary position makes an angle with the objective vertical, and that angle grows with the eccentricity of the tertiary position.1 This geometric tilt is sometimes called false torsion or pseudotorsion, and confusing it with true cyclorotation has caused much trouble in the literature.1

Sources (9)
  1. Binocular Vision and Ocular Motility, ch. 4
  2. Kanski's Clinical Ophthalmology (2024), ch. 18
  3. Binocular Vision and Ocular Motility, ch. 12
  4. American Academy of Ophthalmology. 2020. Pediatric Ophthalmology/Strabismus: Basic and Clinical Science Course. San Francisco: American Academy of Ophthalmology.
  5. Ansons, A.M. and Davis, H. eds. 2014. Diagnosis and management of ocular motility disorders. 4th ed. Oxford: Wiley-Blackwell.
  6. Noorden, G.K. and Campos, E.C. 2002. Binocular vision and ocular motility: theory and management of strabismus. 6th ed. St. Louis: Mosby.
  7. Rutstein, R. and Daum, K. 1997. Anomalies of Binocular Vision: Diagnosis & Management. St. Louis: Mosby.
  8. Rowe, F.J. 2012. Clinical orthoptics. 3rd ed. Oxford: Wiley-Blackwell.
  9. Von Noorden, G.K. and Campos, E.C. 2002. Binocular vision and ocular motility: theory and management of strabismus. 6th ed. St. Louis: Mosby.

Reviewed October 2026

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