adduction
Adduction is the rotation of one eye toward the nose about the eye's vertical axis. Adduction is one of the four cardinal duction movements, and its opposite is abduction, the rotation toward the temple.1
The medial rectus is the adducting muscle. The medial rectus arises from the annulus of Zinn at the orbital apex, inserts 5.5 mm behind the nasal limbus, and has adduction as its sole action in primary position.2 The oculomotor nerve supplies the medial rectus along with the inferior rectus, superior rectus, inferior oblique, pupillary sphincter and levator.3
More detail
A rough clinical guide judges adduction at the lower lacrimal punctum. In maximal adduction, a vertical line through the lower punctum should fall at the boundary between the inner third and the outer two thirds of the cornea. If more cornea is hidden, adduction is excessive, and if sclera remains visible, adduction is defective.4
Sources (8)
- von Noorden and Campos, Binocular Vision and Ocular Motility, ch. 4
- Kanski, Clinical Ophthalmology (2024), ch. 18
- Liu, Volpe and Galetta, Neuro-Ophthalmology: Diagnosis and Management, ch. 15
- von Noorden and Campos, Binocular Vision and Ocular Motility, ch. 12
- Rutstein, R., Daum, K. (1997). Anomalies of Binocular Vision: Diagnosis & Management, Mosby.
- Gunton, K. B. (2015). Dissociated vertical deviation: clinical features, associated abnormalities, and a new pathogenetic concept. Eye, 29(2), 213-220.
- Riordan-Eva, P., & Whitcher, J. P. (2008). Vaughan & Asbury's general ophthalmology. McGraw-Hill Medical Pub.
- Kushner, B. J. (2017). Diagnosis and treatment of diplopia. In Pediatric Ophthalmology and Strabismus (pp. 1023-1046). Springer, Berlin, Heidelberg.
Reviewed October 2026