A retrospective study was made of the case-histories of 48 patients with late consecutive exodeviations, which had occurred after surgical treatment of a primary convergent squint. An evident predisposition towards the late appearance of the exodeviation could not be demonstrated. In some cases there seemed directly to have been a slight overcorrection, within the limits of operative success. In spite of the attempted overcorrection in a second operation on account of exodrift, recurrence of the exodeviation often occurs.