[Weiss coordimeter: clinical contribution to the study of diplopia].

We used the Weiss' coordimeter for studying the fusional effort of 8 patients presenting asthenopic complaints and intermittent diplopia. This method allows us to compare the latent deviation of the visual axis with and without fusion. We analyse the comparative responses through the cases of two congenital superior oblique palsies, one esophoria and five exophoria. In seven out of the eight cases, we propose an appropriate prismatic treatment.