[Electro-oculographic study of vergence movements (author's transl)].

The study of vergence movements imperatively needs a recording method. Nowadays, in spite of its various drawbacks, electro-oculography is the most accurate method for clinical wants. The authors have studied the refixation vergence along a symmetrical inducing axis. With regard to both eyes in binocular and monocular fixations the analysis of a great lot of recordings in normal patients allows to reveal some phenomena unknown till now. In binocular fixation it is usual to notice a physiologic dyssynergy of vergence movements. The monocular fixations bear out evidence that Hering's Law doesn't apply to vergence movements. On the contrary they are submitted to a complete opto-motor dissociation, because the motor responses fully change according to the modalities of inducing visual inputs. In others respects, the analysis of all recordings proves that a vergence movement is made up with two synkinetic phases: a slow phase which was known for a long time thanks to physiological laboratory works; but also a fast phase having a saccadic feature. The fast vergence is related with a monocular visual attraction reflex and it is not bound only to the macular function.