++
Vision is present at birth (focal depth of only 20 cm) maturing to normal ‘adult’ vision at ~12 mths following maturation of the macula, fovea and retina at ~3 mths.
++
Visual perception gradually matures until ~7 yrs but will be affected by problems such as strabismus and may lead to loss of vision (amblyopia).
++
If best vision is reduced to 6/18 or worse, learning problems can occur at school.
++
Loss of vision in a healthy eye
Can only be treated up to 6 yrs
Main predisposing factor is strabismus
++
Tends to manifest from ~2 wks to 3–4 mths when eye used
Most are sensory with normal muscles
75% are convergent
Affect normal development of binocular vision
++
++
Transient: common in neonates, not a problem
Manifest or constant: always present—a serious problem
Alternating: less serious but requires referral
Latent: evidence under stress (e.g. fatigue, provocative testing)
Pseudo: apparent due to wide epicanthal folds and nasal bridge
++
++
Anisometropia: significant difference in refractive error of two eyes
Astigmatism: variations in corneal curvature (e.g. conical cornea) affects normal focusing of light; needs a corrective lens
Myopia (short sightedness): uncommon in infants and children but progressive in teens; needs glasses with a concave lens or contact lenses
Hypermetropia (long sightedness): mild cases usual in infancy and early childhood—may be associated with convergent squint; correction with a positive converging (convex) lens
++
Referral guidelines (preferably preschool)
++
Amblyopia
Any parental concern, incl. observation of any type of squint
Risk factors (e.g. physical abuse, in utero infections)
Head tilting on testing acuity
Visual acuity 6/12 or worse in one or both eyes
Constant squint
Alternating squint esp. after 6 mths
Latent squints
++
Deafness in children 
162
++
Infants are born with hearing
Normal hearing is essential for speech and language development
The first 2 yrs are critical for this development but most hearing problems detected over these 2 yrs
Hearing aids required by 12 mths in deaf children. Screen at 8 mths or earlier (before 10 mths)