Refractive error incidence in primary school children
It has generally been accepted that there is a direct relationship between
excessively near-work such as writing and reading, and the incidence of myopia in
primary school children.
Hong et al (1967, 1968) reported a yearly increase in the incidence of myopia in
primary school children in Seoul, Korea.
The highest incidence of myopia was found among 5th and 6th graders. These
children had to study hard for long hours in preparation for the entrance
examinations into middle school.
This study was on the incidence of myopia among primary school children was made
to find the present incidence of refractive errors now that the entrance
examination has been eliminated. In Seoul these examinations have been eliminated
since 1969. This study was made in 1973. A comparison is made of the incidence of
refractive errors before and after the elimination of the examination.
Materials and Methods
645 primary school children (330 boys and 315 girls) between the ages of 7 and 12
were examined for refractive errors. Visual acuity was checked using the Snellen's
E chart under a standard 10 foot candle illumination. There after 2% Cyclogyl
solution was twice instilled in both eyes at 5 minute intervals.
The subjective and objective refractive examination was done when the pupils were
fully dilated and there was no reaction to light.
1. Ammetropia was more common than emetropia in all of the studies for primary
school children (1967, 1968, 1973).
2. Hyperopia was more common than myopia in all of the studies of the incidence
of ametropia. (1967, 1968, 1973)
3. The incidence of hyperopia increased until the age of 7 following which there
was an annual decrease in the incidence. In contrast, the incidence of myopia
showed an annual increase from the age of 8 years.
4. Although myopia was more commonly found among the girls in the 1967, 1973
studies, the 1968 study showed a higher incidence among boys.
5. The greatest incidence of refractive errors occurred at the age of 7 years.
6. The majority of refractive errors were less than 3 diopters.
7. "With the rule" astigmatism was more commonly found than "against the rule".
8. In 1973 the incidence of myopia among primary school children had ddropped to
13.7% as compared with a 19.37% incidence in 1967, and 22.9% incidence in 1968.