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Last reviewed: 18 Mar 2025
Last updated: 07 Sep 2023

Summary

Definition

History and exam

Key diagnostic factors

  • presence of risk factors
  • infant not tracking parent's face
  • abnormal red reflex

Other diagnostic factors

  • asymptomatic
  • subnormal visual acuity for age in one or both eyes
  • asymmetric corneal light reflex
  • unequal behavioural response to alternate eye occlusion
  • abnormal cover/uncover testing
  • blurred vision
  • eye strain
  • congenital nystagmus
  • abnormal pupil exam
  • abnormal external eye exam

Risk factors

  • age <9 years
  • strabismus (misalignment of the eyes)
  • opacity in the cornea, anterior chamber, lens, vitreous chamber, or retinal surface
  • severe ptosis or prolonged occlusion of one or both eyes
  • prematurity
  • family history of amblyopia or strabismus
  • hyperopic anisometropia (long-sightedness with unequal refractive error between the 2 eyes) of >+1.50 dioptre
  • myopic anisometropia
  • astigmatism (cylindrical, rather than spherical, defocus of the eye) >2.00 dioptre
  • hyperopia >+4.50 dioptre
  • myopia >-3.00 dioptre
  • developmental delay

Diagnostic investigations

1st investigations to order

  • visual acuity tests (by specialist)
  • stereopsis (perception of depth or 3-dimensionality) and binocular vision testing
  • assessment of fixation, ocular alignment, and ocular motility
  • anterior segment examination using a slit lamp
  • dilated fundoscopy
  • cycloplegic retinoscopy
  • binocular red reflex test (Brückner test)

Emerging tests

  • visual evoked potentials

Treatment algorithm

Contributors

Authors

Irene Gottlob, MD

Professor of Ophthalmology

Department of Neuroscience, Psychology and Behaviour

University of Leicester

Ulverscroft Eye Unit

Leicester Royal Infirmary

UK

Disclosures

IG declares that she has no competing interests. IG is an author of references cited in this topic.

Gail Maconachie, PhD, BMedSci

Lecturer

School of Allied Health Professions, Nursing and Midwifery,

Faculty of Health

University of Sheffield

UK

Disclosures

GM declares that she has no competing interests. GM is an author of a reference cited in this topic.

Eleni Papageorgiou, MD, PhD

Consultant in Pediatric Ophthalmology, Strabismus and Neuro-Ophthalmology

Department of Ophthalmology

University Hospital of Larissa

Larissa

Greece

Disclosures

EP declares that she has no competing interests.

Acknowledgements

Dr Irene Gottlob, Dr Gail Maconachie, and Dr Eleni Papageorgiou would like to gratefully acknowledge Dr Tina Rutar, the previous contributor to this topic

Disclosures

TR declared that she had no competing interests.

Peer reviewers

David Robbins Tien, MD

Associate Clinical Professor of Ophthalmology

Alpert Medical School of Brown University

Director of Ophthalmology

Hasbro Children's Hospital

Providence

RI

Disclosures

DRT declares that he has no competing interests.

David K. Wallace, MD, MPH

Associate Professor of Ophthalmology and Pediatrics

Duke Eye Center

Durham

NC

Disclosures

DKW has received NEI grants of more than 6 figures USD. DKW is an author of a number of references cited in this topic.

Michael Clarke, FRCS, FCOphth

Reader in Ophthalmology

Newcastle University

Newcastle

UK

Disclosures

MC has received NHS research grants of more than 6 figures USD. MC is an author of a number of references cited in this topic.

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