[Clinical application of millimetric cover test (author's transl)]

The strabismic angle can be evaluated by measuring, with a millimeter ruler, the limbus shift of the nonfixating eye by assuming fixation. Each millimeter of temporal limbus shift corresponds to an adduction of about 4.6 degrees, and each millimeter of nasal limbus shift to an abduction of about 4.8 degrees. This technique permits rapid evaluation of the strabismic deviation without disturbing the sensory situation. It is very useful in the estimation of large and variable deviations, of vertical deviations and of the amplitude of nystagmus movements, in cases where the "rebound-saccades" render the prism cover test unreliable, in measurements of horizontal deviation in up and down gaze.