The purpose of this communication is to report a short study of the prevalence of muscle imbalance in cases of myopia and its influence as a causative factor in the onset and progressiveness of this condition.
In an article published in 1895, I1 laid stress on the fact that among the 245 cases of myopia there recorded not one could be described as simple myopia. At least one of three presumably congenital conditions—astigmatism, anisometropia and muscle imbalance—was demonstrable in each. In many cases all three were present. Experience since then has failed to demonstrate any case of myopia in which all these conditions could be positively excluded, and doubt therefore arose as to whether there is such a thing as simple myopia. If there is, it must be exceedingly rare. This refers, of course, only to axial myopia. In cases of myopia there are, therefore, two groups