Device for determining at least one sight parameter of a subject, includes stimulation elements for stimulating the sight of the subject in a predetermined viewing direction, elements for ophthalmological measurement of at least one sight parameter of a subject, the elements for ophthalmological measurement having at most one optical measurement axis for each eye, at least one optical conjugation system, arranged between the ophthalmological measurement apparatus and the right eye and/or left eye of a subject, and a system for aligning the optical conjugation system, so as to optically conjugate a point Y and a point E, the point Y intended to coincide with the optical center of rotation of the eye concerned, the point E being situated on the optical measurement axis, so as to align the image of the optical measurement axis with the ocular axis of the right or left eye in a plurality of viewing directions.
