[Bifocal glasses for non-presbyopic patients (author's transl)]

A disturbance of the physiological relation between accommodation and convergence which is defined by the AC/C ratio results in a manifest convergent squint. After a short reference to the typical accommodative esotropia, the atypical accommodative esotropia ("convergence excess") and its treatment with bifocal lenses are discussed in greater detail. Bifocal glasses are also used in the following disturbances of binocular vision: in partially accommodative convergent squint with a larger deviation in near fixation, in primary and postoperative microtropia with a larger deviation in near fixation, in esophoria with signs of decompensation in near fixation, with an intermittent exotropia of the divergence excess type. In the last-mentioned case they are use exclusively in preoperative diagnostics. The use of bifocals is simple and does not take much time; contrary to cyclospastic drugs, it has no undesirable side effects. Experience has shown that even after wearing bifocals for years there is no danger of a permanent accommodation insufficiency.