弱視児のものの見え方 : そのI.正常児の視力について

抄録

In a series of studies on the vision of partially seeing children, of which this is the first, we propose to present the nature of visual acuity in early age, together with some remarks about the method examing the visual acuity of children. The visual objects used in the test were each independent Landolt's "broken ring." The Landolt's ring was the most suitable to measure the only resolving power of eyes based on the minimum separable. It was quite possible for the children of preschool age to rejoin the direction of the break of the test ring by rotating the model plate held in their hands. Moreover, letters had to be singly shown for the visual tests to get rid of psychic influences. Most of the children aged 4 showed the visual acuity 1.0 or more than that, and it is considered that it has almost attained the area of the visual acuity of adults. And in the children before age 6, however, the development of the visual acuity in average could be recognized though gradually. As for the children aged 6, those of the visual acuity more than 1.0 covered as high as 96% having statistically the peak of 1.5 in visual acuity.