A pair of field glasses when looked through will sometimes show a double object. This double image is due to the directions of the two optic axes not being in correct relation. This prevents the rays from the image converging upon the fovea? of both eyeballs simultaneously, two different pictures being presented, one to each eye. The remedy is to alter the direction of the optic axis of one of the telescopes forming the field glass. Probably the joining bars are bent, and so obviously they should be straightened.