A binocular multiplexing device combined to an ophthalmological instrument having several objective measuring channels of at least one visual parameter of a subject, said ophthalmological instrument comprising an illumination mean able to emit a binocular illuminating beam, means for collecting a measuring beam generated by reflection and/or refraction of said illuminating beam from an eye of the subject, and a sensor associated with a single measuring channel, the illumination mean being separated from said sensor, said binocular multiplexing device comprising: - first optical splitting means able to receive a stimulating image beam issued from a stimulus test pattern and intended to stimulate accommodation by the subject, said first optical splitting means being able to split said stimulating image beam into a right ocular stimulating beam and a left ocular stimulating beam so as to stimulate accommodation by the right eye and left eye of the subject simultaneously; - second optical splitting means able to receive said binocular illuminating beam and to split said binocular illuminating beam into a right monocular illuminating beam and a left monocular illuminating beam, said right monocular illuminating beam and respectively said left monocular illuminating beam being intended to illuminate the right eye and the left eye of the subject, respectively, in order to form, after reflection and/or refraction from the eye (12, 13) in question, a right ocular measuring beam, respectively a left ocular measuring beam; - an optical switch placed outside the optical path of the right ocular stimulating beam, left ocular stimulating beam, right monocular illuminating beam and left monocular illuminating beam, said optical switch being able to receive said right ocular measuring beam and respectively said left ocular measuring beam and to steer in sequence said right ocular measuring beam or respectively said left ocular measuring beam, toward said sensor associated with said single measuring channel, when the right monocular illuminating beam and respectively the left monocular illuminating beam illuminate simultaneously the right eye and the left eye of the subject; - first optical combining means able to superpose the right ocular stimulating beam and the right monocular illuminating beam, and first optical means for directing the right ocular stimulating beam and the right monocular illuminating beam toward the right eye; and - second optical combining means able to superpose the left ocular stimulating beam and the left monocular illuminating beam, and second optical means for directing the left ocular stimulating beam and the left monocular illuminating beam toward the left eye. - first optical splitting means able to receive a stimulating image beam issued from a stimulus test pattern and intended to stimulate accommodation by the subject, said first optical splitting means being able to split said stimulating image beam into a right ocular stimulating beam and a left ocular stimulating beam so as to stimulate accommodation by the right eye and left eye of the subject simultaneously; - second optical splitting means able to receive said binocular illuminating beam and to split said binocular illuminating beam into a right monocular illuminating beam and a left monocular illuminating beam, said right monocular illuminating beam and respectively said left monocular illuminating beam being intended to illuminate the right eye and the left eye of the subject, respectively, in order to form, after reflection and/or refraction from the eye (12, 13) in question, a right ocular measuring beam, respectively a left ocular measuring beam; - an optical switch placed outside the optical path of the right ocular stimulating beam, left ocular stimulating beam, right monocular illuminating beam and left monocular illuminating beam, said optical switch being able to receive said right ocular measuring beam and respectively said left ocular measuring beam and to steer in sequence said right ocular measuring beam or respectively said left ocular measuring beam, toward said sensor associated with said single measuring channel, when the right monocular illuminating beam and respectively the left monocular illuminating beam illuminate simultaneously the right eye and the left eye of the subject; - first optical combining means able to superpose the right ocular stimulating beam and the right monocular illuminating beam, and first optical means for directing the right ocular stimulating beam and the right monocular illuminating beam toward the right eye; and - second optical combining means able to superpose the left ocular stimulating beam and the left monocular illuminating beam, and second optical means for directing the left ocular stimulating beam and the left monocular illuminating beam toward the left eye.