Squint (strabismus)


These guidelines have been produced to guide clinical decision making for general practitioners (GPs). They are not strict protocols. Clinical common-sense should be applied at all times. These clinical guidelines should never be relied on as a substitute for proper assessment with respect to the particular circumstances of each case and the needs of each patient. Clinicians should also consider the local skill level available and their local area policies before following any guideline.

Any acute onset squint should be referred immediately

Call PCH Switch on 6456 2222 and ask for the Ophthalmology registrar on call



Often wrongly referred to as having a lazy eye, strabismus (or squint) is a condition in which both eyes do not point in the same direction. It is further classified by the direction the eye turns - inwards (esotropia) or outwards (exotropia), up or down, if it is constant or intermittent, unilateral or bilateral, alternating or the same eye all the time.

Causes of strabismus include congenital cases with no known cause, genetic conditions, abnormal in utero development, uncorrected refractive errors, eye or head injury and can occasionally be a sign of a more serious underlying condition. Risk factors include prematurity, family history of strabismus and other eye abnormalities. 

Symptoms can include eyes appearing:

  • misaligned
  • uncoordinated eye movements
  • double vision
  • loss of vision or depth perception. 

Untreated strabismus can cause amblyopia and vision loss. Early diagnosis and treatment provides the best outcome and promotes the development of normal binocular vision. 

Pre-referral investigations

  • Conduct a visual acuity examination if age appropriate. For younger children use a light or toy to look for fixing and following. Check each eye separately.
  • Check eye movement using verbal commands, a light or a toy. Look specifically for eye alignment
  • Conduct an eye assessment including pupil reaction and fundus examination.

Pre-referral management

  • No pre-referral management required

When to refer

Refer to the Ophthalmology Department:

  • Constant strabismus in any age child
  • Intermittent strabismus in any child aged over 3 months of age 

How to refer

  • Routine non-urgent referrals from a GP or a Consultant are made via the Central Referral Service
  • Routine non-urgent referrals from optometrists or doctors at private hospitals are made via the PCH Referral Office.
  • Urgent referrals (less than seven days) are made via the PCH Referral Office. Please call Perth Children’s Hospital Switch on 6456 2222 to discuss referral with the relevant speciality registrar. 

Essential information to include in your referral

  • Age that strabismus originally noted (earlier onset common in congenital conditions)
  • Details of strabismus including intermittent or continuous, direction, same or alternating eye
  • Any family history
  • Any history of head or eye injury
  • Visual acuity exam result including any changes to visual acuity
  • Any behavioural or developmental issues that may have an impact on ease of assessment, (Autism, Developmental delay, ADHD)
  • Medical and surgical history.

Useful resources


  1. Granet DB, Khayali S. Amblyopia and Strabismus. Pediatric Annals. 2011;40(2):89-94.
  2. Gunton KB, Wasserman BN, Debenedictis C. Strabismus. Primary care. 2015;42(3):393-407.
  3. Perth Children's Hospital. Strabismus. In: Perth Children's Hospital, editor.: Child and Adolescent Health Service,; 2020.

Reviewer/Team: Ophthalmology Department, PCH Last reviewed: March 2024
Endorsed by:
CPAC Date:  March 2024

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