Studies on Mild School Myopia Part Ⅱ. The Amplitude of Accmmodation in Mild School Myopia

By examining 160 eyes of 80 students with mild myopia (under3D) age ranging from 12 to 25 years and as the controls 60 eyes of 30 students from 19 to 25 years for their refraction, accommodation amplitude, and the degree of asthenopia, the author obtained the following results: 1. The amplitude of accommodation in myopia is weakened as compared with that of normal eyes. 2. The younger the students with mild school myopia the more marked is the difference in the accmmodation amplitude when compared with that of the control, but this difference lessens as students approach 25 years old. This seems to be the result of strengthening of the accommodation amplitude in older students because they wear eyeglasses. 3. The fluctuation in near point and the weakening of accommodation amplitude have been found in 41.8 per cent of myopia whereas 0 per cent in the control, thus indicating the presence of ciliary muscle dysfuncton in mild myopia. 4. In mild myopia the degree of refraction and the accommodation amplitude are in converse relationship, namely, it has been confirmed that the stronger the degree of myopia, the weaker is the amdlitude of accommodation. 5. There is no mutual ralationship between the weakening of the accommodation amplitude and the degree of asthenopia in mild myopia.