Abstract: An apparatus for determining the distance between the pupils to yield values representative of lenses properly aligned with the patient's pupils when mounted in the sockets of a spectacle frame. The apparatus consists of a calibration device having spaced fixed marking for placement in the plane of lenses, a camera with a zooming arrangement for taking an image of the subject, and a computer for generating parametric values relevant to the lenses to be ground as a function of the distance between the camera and the subject, the position of the zooming device at the time the image is taken, and the size of the image on the focal plane of the camera.

Abstract: An apparatus for determining the distance between the pupils to yield values representative of lenses properly aligned with the patient's pupils when mounted in the sockets of a spectacle frame. The apparatus consists of a calibration device having spaced fixed marking for placement in the plane of lenses, a camera with a zooming arrangement for taking an image of the subject, and a computer for generating parametric values relevant to the lenses to be ground as a function of the distance between the camera and the subject, the position of the zooming device at the time the image is taken, and the size of the image on the focal plane of the camera.