THERE seems to be an increase in the incidence of divergence insufficiency. This may be due to stimulated interest and improving diagnostic acumen. However, it may be the result of increase in certain types of brain stem involvement produced by automobile injuries, virus encephalitis, and vascular lesions occurring in advanced years—very different causes, which have furnished a number of the cases in the recent series we have studied.
Another reason for this discussion of this subject is the revelation of investigators who have rather definitely proved that divergence function is an active process, and not merely the result of convergence relaxation or the return to the rest state of ocular muscle balance. Adler and his co-workers demonstrated that an actual change, an increase in electrical potential, took place in the lateral rectus muscle when the eye was moved from a convergent to a less convergent position.1
A study of
LYLE DJ. DIVERGENCE INSUFFICIENCY. AMA Arch Ophthalmol. 1954;52(6):858-864. doi:10.1001/archopht.1954.00920050864007