An object is to simply and easily evaluate differences in behavior of the eyes of subjects. A binocular measurement system 1 includes a photodetector 7 that detects reflected light from the right eye ER and the left eye EL of a subject, and outputs image signal of the reflected light, a feature amount calculating unit 11 that calculates a feature amount corresponding to the right eye ER and a feature amount corresponding to the left eye EL based on the image signal, and a comparison value calculating unit 13 that calculates, based on the two feature amounts, a comparison value obtained by comparing the two feature amounts.