[New method of prismatic prescription in diplopia].

This paper presents the case of a man with resulting diplopia due to multiple lesions of the extraocular muscles after an orbital trauma. The intact ocular globe has an horizonto-vertical strabismus. Purpose was the reduction of diplopia in primary gaze. The original contribution of the authors is the new method of prescription for the prismatic lenses, for the best results in glasses execution. A mathematical model of vectorial composition for light deviation through a system of prismatic lenses, is proposed.