Abstract: A progressive opthalmic lens is disclosed which has an upper part of constant refractive power for distance vision and a lower part of progressively variable refractive power for near vision. In order to increase the effective field of intermediate vision while providing smooth transition between the upper and lower parts of the lens for the user, an additional segment providing a local addition of refractive power is superposed on at least a portion of the progressive variable power zone of the lens. The additional segment may comprise an insert or a protuberance on the progressive portion which may be formed as a surface film on a blank base or substrate. The additional segment may have constant refractive power or include a progressively variable refractive power area.

Abstract: Grinding machine of the copying type for grinding a concave surface of an article such as a lens blank, comprising a templet having a concave surface identical with that to be obtained on the article and with a mean sphere. The machine also comprises a pair of supports for the templet and the article, respectively, which are both rotatably driven in synchronism about two parallel axes, a movable copying head carrying a pin-point contact feeler engageable with the templet and a rotatably driven grinding wheel, and means for guiding the copying head so as to impart thereto a component of movement of rotation about fixed axis passing through the center of the mean sphere of the concave surface of the templet. This axis is parallel to a straight line passing through the centers of symmetry of the feeler and grinding wheel, while the distance between said straight line and the fixed axis is variable.