angle of anomaly
The angle of anomaly is the difference between the objective and subjective angles of deviation in anomalous retinal correspondence.1,2 The angle of anomaly measures the degree of shift in visual directions between the two eyes.3
The objective angle is the manifest deviation measured objectively, as on the cover test. The subjective angle is the deviation as the patient perceives it, judged from any diplopia.2 In harmonious anomalous correspondence the subjective angle is zero, so the angle of anomaly equals the objective angle and the sensory adaptation is complete.2,3 In unharmonious correspondence the angle of anomaly is smaller than the objective angle, and the subjective angle lies between zero and the objective angle.3 Only the harmonious form shows binocular responses, and the unharmonious form may reflect a lesser adaptation or a testing artifact.1
The angle of anomaly is measured on the synoptophore. The examiner finds the objective angle by lighting each target alternately and moving the slide until the eyes stop moving. The subjective angle is the setting at which the simultaneous perception slides superimpose.1
More detail
The objective angle under everyday viewing is the habitual angle, and the objective angle after prolonged dissociation is the total angle. As the habitual angle increases to the total angle, the angle of anomaly usually stays constant.2 In the development of anomalous correspondence, the angle of anomaly gradually increases until it equals the deviation and the correspondence becomes harmonious.3 In some patients the angle of anomaly adapts almost instantly to a change in the deviation, and in others it stays unchanged for decades.3
Sources (7)
- Kanski's Clinical Ophthalmology (2024), ch. 18
- Pickwell's Binocular Vision Anomalies, ch. 12
- von Noorden and Campos, Binocular Vision and Ocular Motility, ch. 13
- Noorden, G.K. von and Campos, E.C. (2002) Binocular Vision and Ocular Motility: Theory and Management of Strabismus. 6th edn. St. Louis: Mosby.
- Bhola, R. (2006) Binocular Vision. Available at: https://webeye.ophth.uiowa.edu/eyeforum/tutorials/bhola-binocularvision.htm (Accessed: 4 May 2024). secondary
- EyeWiki (2023) Anomalous Retinal Correspondence. Available at: https://eyewiki.aao.org/Anomalous_Retinal_Correspondence (Accessed: 4 May 2024).
- Rutstein, R., Daum, K. (1997) Anomalies of Binocular Vision: Diagnosis & Management, Mosby, pp. 347.
Reviewed October 2026