Abstract: A sunglass or eye protector molded from suitable optical material with inner and outer surfaces, both of which are noncircular in the horizontal direction and curved in the vertical meridian to provide substantially uniform thickness throughout.

Abstract: A progressive addition lens constructed on the bipolar principle in accordance with a power law having a steeper slope or gradient in the regions adjacent to the poles than in the middle region thereof between the poles.

Abstract: A progressive power lens series in which the surface of each lens body has first and second vision portions which differ in power in accordance with a power curve which lies entirely in the y-z plane of a Cartesian coordinate system and which is the umbilical portion of the principal meridian of the progressive surface with the curvature of the surface in at least one of said vision portions spreading away from the power curve in accordance with a spreading function defined by the intersection of nested non-bipolar conic sections or nested hyperbolic cosines with the x-y plane of the coordinate system.

Abstract: A method and associated system for providing interference patterns generated from light, including visible, ultraviolet and infrared, carrying desired information comprises the steps of and associated apparatus for modulating a light beam emanating from a suitable source, in accordance with the desired data or information or signal, splitting the modulated light beam into a pair of component beams, both thereby derived from the modulated beam, reflecting the resultant split beams towards each other so as to interfere optically. Advantageously, beam splitting and reflection may be effected by an essentially integrated, transparent element. Also advantageously, a recording of such interference is made by a positioning photosensitive medium at the point or in the plane of interference.