ABSTRACT
We studied the refractive state of 1440 eyes, 720 children (360 boys and girls in each) of T primary school in Busan and 720 eyes, 360 children (186 boys and 174 girls) of S primary school in Geu-Chang, Keung Nam. We neglected small refractive errors up to 0.5 Diopter because there was mathematical error in spite of exact clinical measurement of ocular refractive powerunder cycloplegia. The results were as follows: 1. Incidence of refractive errors of children (7 to 12 years) was 37.7 and 27.8% in T and S primary school respectively. 2. Incidence of myopic eyes was 25.6 and 13.6% in T and S primary school but that of hyperopic eyes was 11.7 and 14.2% respectively. Incidence of refractive errors and myopic eyes of children between T and S primary school showed significant difference. 3. The greatest incidence of refractive errors was at the age of 7 years but there was no significant difference at the age of 8 to 12 years. 4. The degree of refractive power of children in T and S primary school was 95.9 and 96.1% of hyperopia and 74.5 and 83% of myopia under 1.0 Diopter respectively. 5. Incidence and the degree of refractive power in myopia showed tendency of an increase in proportion to the age of 8 to 12 years. 6. The incidence of myopic eyes was not related to body weight and height of children of both sex.