Describe childhood blindness and school eye health.

Childhood Blindness

• Childhood blindness is a priority out of all proportion to its numbers, and the reason is arithmetical: a child blinded at five and living to seventy accrues sixty-five blind-years. Measured in blind-years, childhood blindness is second only to cataract in global burden
• The prevalence tracks the under-five mortality rate — 0.3 per 1,000 children in wealthy countries and 1.5 per 1,000 in the poorest — because the same poverty, malnutrition and infection produce both. Where children die, children go blind
• The causes change with development.

School Eye Health

• School eye screening is one of the highest-yield activities in the entire national programme.
• The model — teachers are trained to test visual acuity, with a snellen or E chart at 6 metres, referring any child who cannot read 6/9; an ophthalmic assistant confirms and refracts; and free spectacles are dispensed under the national programme
• Using teachers is the key design choice: they are already present, know the children, cost nothing additional, and can screen an entire school — whereas an ophthalmologist could never reach that population. The trade-off is a lower specificity, corrected at the second stage
• Target ages — screening is most valuable at school entry (5 to 6 years) and again in early adolescence, when myopia develops and progresses
• The limiting problem IS not detection but spectacle wear, and this is the point most often missed. A large proportion of children given free spectacles are not wearing them at follow-up. The reasons are consistent: teasing and stigma; a belief that spectacles weaken the eyes or that vision will deteriorate with wear; parental disapproval, particularly for girls, sometimes with concern about marriage prospects; breakage and loss; poor frame fit and appearance; and the child not perceiving a benefit
• What actually improves wear — counselling the parents as well as the child; letting the child choose the frame, which markedly improves compliance; good fitting; involving the teacher; addressing the myth that spectacles weaken the eyes explicitly; and free replacement of broken pairs
• Myopia is increasing worldwide and in urban India, associated with intensive near work and reduced time outdoors. Increased outdoor time is the best-evidenced preventive measure, and about two hours a day is the commonly cited target; myopia control with atropine, specialised spectacle lenses and orthokeratology is used for progression
• School screening should also detect squint, colour vision defects, vitamin A deficiency, trachoma where endemic, and conjunctivitis; and eye health education can be delivered through the same visit
• A child blinded at five accrues sixty-five blind-years, which is why childhood blindness ranks second only to cataract in global burden
• Childhood blindness tracks under-five mortality; where children die, children go blind, and for the same reasons
• The causes shift with development from corneal scarring, to retinopathy of prematurity, to genetic and cortical causes
• India shows the third epidemic of retinopathy of prematurity in bigger and more mature babies than Western criteria anticipate
• The critical period makes delay irreversible; a late cataract operation leaves amblyopia that perfect surgery cannot undo
• Paediatric services must be fast as well as available, which is a different requirement from adult cataract services
• Red reflex screening is the only test for congenital cataract and retinoblastoma, takes seconds and is repeatedly omitted
• Harmful traditional eye remedies cause corneal scarring, and asking about them is part of every paediatric eye history in rural practice