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Primary Care Liaison

Abnormal pupil reaction and size

  • The following pre-referral guideline covers abnormal pupil reactions and size.  Please see other ophthalmology guidelines as needed including Abnormal red reflex/white pupil.

    See resources for referral form, parent information and more.

    Pre-referral assessment/treatment

    1. Assess pupil reactions and sizes
    2. Check visual acuity if child of an appropriate age. If the child is too young to check visual acuity, ascertain whether the child can fix and follow - for toddlers try a toy, for infants try a toy or a light.
    3. Check ocular motility - ask child to look at the roof, down at the ground, and side-to-side. If child too young, again try a toy or a light.
    4. Perform fundus examination and note presence/absence of red and white reflex.

    Initial findings and when to refer

    1: Asymmetric pupillary reactions

    • Please call 03 9345 6180 AND fax referral to 03 9345 5034 (number also on referral form).

    2: Asymmetric pupillary size

    Physiologic anisocoria - less than 1mm difference under light-adapted or dark-adapted conditions

    • Refer non-urgently

    Oculomotor paresis - associated limitations of eye movement on the side with the larger pupil

    • Refer semi-urgently

    Horner's syndrome - greater than 1mm difference between the eyes under light-adapted and under dark-adapted conditions. There may be an associated eyelid droop and lighter iris coloration on the side with the smaller pupil.

    • Refer semi-urgently

    Contact information

    RCH Switchboardtelephone (03) 9345 5522

    For clinical advice ask for:

    • Ophthalmology registrar or consultant on-call
      • Department of Ophthalmology - clinical advice (or direct dial 03 9345 5630)
      • Emergency Department - for clinical advice after hours
    For outpatient bookings fax to 03 9345 5034 (number also on referral form)
    • For urgent appointments also call 03 9345 6180

    Admission enquiries ask for:

    • General admission enquiries (or direct dial 03 9345 6172)
    • ED admission enquiries: (or direct dial 03 9345 6477)



    Guideline developed by the RCH Department of Ophthalmology in consultation with a GP Review Group. Many thanks to the GPs involved in the review.   Feedback

    Please give feedback on this guideline - / telephone: (03) 9345 4645 / fax (03) 9345 4650

    Last updated

    Last update: August 2011

    First published Nov 2007. Reviewed August 2009.Please read  Copyright and Disclaimer.