On the distribution of colorblindness in Island Sado.

Abstract

In Island Sado, the author's native place, the percentage occurrence of Colorblindness among school b, ys and girls, 9 to 13 years 'old, was Lund as follows :
It is remarkable that this anomaly is so concentrated in the southern district. The term “colorblindness” is here used in a broader sense, as it is applied to any abnormal result of the color-plate test 4fter Ishihara.