Paediatric Vision

• Key Stages in a Paediatric Eye Exam

  1. History

  2. Visual function (vision and VA and if needed contrast sensitivity)

  3. Refraction Often cycloplegic

  4. BV status

  5. Colour vision if needed

  6. Anterior segment and fundus exam

  7. Short attention span so may need to call back on another day
• Examining Infants and Children

  1. Look at them in waiting area

  2. Squint? How do they loo through glasses?
• History Taking


  1. Tailor to child's age

  2. Introduce yourself

  3. Talk to the child if appropriate

  4. Childs eye level

  5. Use Childs name

  6. Always praise

  7. No white coat

  8. Toys

  9. Why has the child come? Routine/worries

  10. FLOADS

  11. Past OH

  12. FH

  13. Birth history important=pre-term/full term/weight/type of delivery/maternal illness during pregnancy

  14. Establish normal milestones

  15. Medical hx/meds/allergies

  16. Tailor to child when appropriate

  17. Use child friendly language when appropriate
• VA testing


  1. Electrophysiological testing - don't normally do on high street

  2. Behavioural testing- observe child

  3. Where possible, measure monocularly

  4. Observe occlusion behaviour

  5. Usually from 3 months

  6. Child will object to 'good'eye being covered
• Electrophysiological testing


  • Visual evoked potentials
  • Flash VEP stimulus
  • Pattern VEP stimulus
  • Look at response
  • Get latency and see if it's a normal value
  • Objective method
• Preferential looking


  • Fantz et al, 1962
  • 'Infants prefer to look at a pattern than a blank stimulus'
  • Age 0-24 months
  • Use iso-illuminant stimuli= card with black and white grating with a circle that is plain
  • Principle based on resolution tests=ability to detect and resolve a target
  • Ability to discriminate different spatial frequencies or other metrics
  • Spatial freq= cycles/degree, uses sine wave gratings
  • Narrower stripes=higher spatial freq
  • Less sensitive to amblyopic defects esp in strab
  • Doesn't have any crowding
• Preferential looking tests


  • Teller acuity cards
  • Keeler acuity cards
  • Lea grating paddles
  • Cardiff acuity cards
• Keeler acuity cards


  • W.d=38cm
  • Usually 15 cards with black and white stripes on right/left side, 1 blank card
  • 4mm hole in centre
  • Range 0.32 to 38 cycles per degree
  • Start with low spatial freq and move in 1/half octave steps up (if correct response Or down if incorrect response)
  • Correctly identifies same stimulus twice means the child can resolve that card
  • Clinical sig interocular difference: greater than/equal 2 cards. Means what is the difference between 2 eyes before you think theres a problem
• Preferential looking tests


  • Peekaboo app
• Peekaboo app


  • 2 forced choice/4 forced choice, livingstone et al 2019
  • Free iPad app
  • Touching pattern results in a yippeee sound and cartoon appears=+ feedback
  • W.d 25-50cm
  • VA measured 0.2-1.3 logMAR
  • Results comparable to keeler
• Older Children 2 years +

  1. Recognition acuity: ability to detect, resolve and recognise a target

  2. More sensitive to amblyopic defects esp in strab and crowded targets

  3. 2 years= picture matching

  4. 3 years= picture/letter matching

  5. 3 years += naming too

  6. Matching cards can be supplied at home for practice before clinic
• Tests for Older Children


  • Kay Pictures
  • Lea symbols
  • Letter Matching Tests
  • Keeler logMAR crowded test
• Kay Pictures


  • Common objects
  • Single pics/crowding in logMAR format (3m)= 1.0-0.1 logMAR
  • Single pictures In snellen format (3/6m)
  • 3/3 (6/6)-3/30 (6/60)
  • Each line equivalent to 0.1 logMAR acuity
  • Tests on iPad
  • Clinical significant interocular difference (crowded): greater than 3 pictures (less than 4 years)
  • greater than 1 pictures=4 years +
• Lea symbols


  • Same principles as logMAR
  • Single and crowded version
  • Test distance: 3m
  • Test symbols: simple shapes familiar to small chn which blur equally
  • Square, house, circle, apple
  • 0.10-2.0 logMAR
• Letter Matching Tests


  • Sheridan-gardiner test
  • Single letters 6m, can be performed closer
  • Uses flip chart
  • No crowding
  • Linear letters with crowding available
  • 6/60-6/4
  • Cambridge crowded acuity test
  • Uses Sheridan-gardiner letters 3m/6m
  • Identify letter which is surrounded by 4 others
  • Crowding
  • Tumbling E/Landolt C
• Keeler logMAR crowded test

  • Flip-chart
  • 6/38 (0.80) to 6/3 (-0.30)
  • 3m
  • LogMAR
  • Screening and uncrowded available
  • Similar to sonsken silver but more crowding
  • Clinically sig interocular difference: 0.1 logMAR
  • Sonsken= 0.125 log MAR
• Other methods


  • Bradford visual function box
  • Hundreds and thousands
• Bradford visual function box


  • Variety of targets of different sizes
  • Useful when nothing else work
  • Observe to see if child is fixating
• Hundreds and thousands

  • 6months +
  • Isnt really used anymore
  • Small cake décor held in hand
  • See if child is interacting
• Cardiff Contrast Sensitivity Test


  • Same vanishing optotypes as the Cardiff acuity
  • 50cm
  • 3 cards at each contrast level from 46% to 1% in 12 steps
  • Use preferential looking test (PLT) or naming depends n age
  • 12 months + but maybe younger
• Hiding Heidi


  • 5 contrast levels: 25%, 10%, 5%, 2.5%, 1.25%
  • 2 cards: white one and Heidi
  • Use PLT/matching/naming depending on age
  • 0 months +
  • Variable w.d
• SpotChecks Contrast Sensitivity test

  • Inexpensive
  • School chn/pre school
  • Accuracy compared to Pelican-robson
  • Mark where kid can see grey spot
  • Lowest line=measurement
• Cover test


  • Gold standard
  • Interesting target
  • Ask q's
  • Use palm/thumb to occlude
  • Common to have XOP at near
• Hirschberg test


  • Useful if CT is difficult
  • Flash light on and off to encourage fixation
  • Temporal reflex=SOT
  • Nasal reflex=XOT
  • Higher reflex=suggests hypotropia
• EOM


  • Useful
  • Interesting target
  • V small chn-may need to move child rather than target as may not understand
• Motor fusion


  1. 20 BO test

  2. Either eye in turn fixating suitable target

  3. Eye behind prism should adduct and restore fusion and abduct again on removal

  4. Speed of fusion movement helps establish binocularity

  5. Abnormal response: no movement=either no fusion/lack of attention. Slow to overcome prism/slow rec=poor fusion
• Sensory fusion


  • Worths lights
  • Bagolini
• Near point of convergence


  • Gross convergence ability
  • Good target
  • 6 months +
  • Move target towards child until 1 eye turns out/eyes converge
  • Normal depends on age
  • Chn/younger adults= <6cm
  • Break 5cm
  • Recovery 7cm
• Stereopsis tests


  • Langs 2 pen/stereo test
  • Stereo=random dot/no specs/good screening
  • Lang 1 at 40cm=1200'' to 550''
  • Lang 2 at 40 cm= 600''-200''
  • Frisby
  • TNO
  • Titmus
  • Randot
• Accommodative Amplitude/Range


  • Minus lenses
  • Near point
• Accommodative Facility


  Flipper lenses
• Accommodative Lag or Lead


  • Young chn
  • Dynamic ret
  • Objective
  • Lag (under accom is normal approx +0.75DS)
  • Lead (over Accom abnormal)
  • MEM/notts
  • Good for special needs
• Cycloplegic Refraction


  1. >12 months=cyclopentolate 1%

  2. 6-12 months light irides= cyclopentolate 0.5%

  3. 6-12 months dark irides=^ 1%

  4. 3-6 months= ^ 0.5%

  5. Not for kids with hx of epilepsy

  6. If no sign of mydriasis in 10 mins, can use 2nd drop

  7. If needed proxymetacaine 0.5% can be used before instilling cyclopentolate to improve tolerance and cycloplegic affect
• Cycloplegic Refraction


  Advantages: Relaxes accom = better estimation of refractive error, Accurate fixation not need, Large pupil=view of fundus

  Disadvantages: Temp blurred vision, Photophobia
• Near Mohindra Refraction


  1. Occlude 1 eye

  2. Room=dark!!!

  3. 50cm

  4. Ret as normal, neutralise all meridians

  5. Original study suggests correction factor +1.25DS

  6. Saunders and westall 1992=+1.00DS over 24 months and +0.75DS if younger

  7. Repeat for other ye

  8. Observe pupil

  9. Quality of reflex

  10. Co-op
• Colour Vision


  • Cant do in infants
  • Colour vision testing made easy=gold standard for identifying RG colour vision defects
  • Pseudoisochromatic principles
  • 3 years +
  • One demo plate and 9 test plates
  • Good validity when compared to Ishihara
• Anterior Segment Eye Exam

  1. Observe Red reflex/pupil reflex

  2. Burton lamp

  3. Use portable slit lamp if available

  4. 20D lens with mag

  5. Regular slit lamp with kid in parent lap

  6. IOP: tono pen/digital palpitation
• Fundus Examination


  1. Dilated is better

  2. Infants younger than age 1: 0.5% tropicamide and 1 drop 2.5% phenylephrine

  3. If cycloplegic refraction also then 0.5% cyclopentolate

  4. 1year +: 1.0% tropicamide/1% cyclopentolate

  5. Indirect ophthalmoscopy
• Positive family history of strabismus


  Prescribe all the cylinder and some hyperopia
• Refractive error from birth to 3 years


  1. 3-12 months: fast emmetropisation phase

  2. Emmetropia/low hyperopia: little change

  3. Higher ametropia likely to retina

  4. Rate proportional to initial error

  5. 2/3 of astigmatism lost between 9-21 months

  6. Higher levels of anisometropia so up to +3.00DS likely to remain