laser works on the principal of light..the transmitted laser should come back to the detector. simple principal..why the need of a binocular? if you have a long range of distance to measure try an ultrasonic module, gives you approx range of 5m at 70 degree.
Point the laser beam at the object whose distance from you you is required. Focus the binoculars on the laser beam, ensure the image is sharp. The distance marking on the binoculars will indicate the distance of the object.