A series consisting of 411 non‐selected school children, 7 to 15 years of age, was examined. Decreased visual acuity (less than 0.8 in one or both eyes without correction) was found in 55 children (13.4%), the frequency increasing from 3.7% to 29.1% with age. The frequency of hyperopic eyes (+2.0 D. or more) decreased from 19.1% to 3.6% and the frequency of myopic eyes (‐0.5 D. or more) increased from 1.9% to 21.8% with age. Altogether, myopia, hyperopia, or astigmatism (1 D. or more) in one or both eyes was found in 93 children (22.6%).
Manifest strabismus was found in 19 children (4.6%), and heterophoria (8 prism dioptres or more for near or distance) in 28 cases (6.8%), increasing significantly with age, from 1.2 to 13.6%. Amblyopia (visual acuity 0.6 or less) due to strabismus or refractive errors was found in 5 cases. Subnormal vision due to congenital nystagmus, unilateral macular scar, congenital rubella retinopathy and unilateral Coats' disease was diagnosed with one case of each. Signs of external inflammatory disease were seen in 13 cases.
In this series the annual need for ophthalmological consultation increased from 5% at the age of 7–8, to 30% of the children aged 14–15, if follow‐up examinations and visits for the prescribing of glasses were included.