Abstract: The manufacture of an artificial optical lens having any given power profile starts from an artificial optical lens having a different power profile. A physical-chemical treatment method modifies the power profile to obtain a required power profile. A rotating mask is used for spatial modulation of the energy flux.

Abstract: The proximity P of a simultaneous vision optical lens for correcting presbyopia is defined as the reciprocal of the distance D at which a light ray parallel to and at a distance h from its axis crosses the axis after passing through the lens. The curve representing the proximity P of the lens lies between a lower envelope curve P.sub.inf and an upper envelope curve P.sub.sup satisfying the following equations:P.sub.inf =f(h)=(.SIGMA.A'.sub.i h.sup.i)+P.sub.VLP.sub.sup =f(h)=(.SIGMA.A".sub.i h.sup.i)+P.sub.VLin which P.sub.VL is the proximity for distant vision and A'.sub.i, A".sub.i are numeric coefficients depending on the proximity addition added for near vision to the proximity for far vision. The lens may be implemented as a contact lens, an intra-ocular implant or an intra-corneal lens.

Abstract: A progressive ophthalmic lens with a continuous progressive surface comprises a substantially constant power first area matched to far vision. It also has a substantially constant power second area matched to near vision. Between the first and second areas is a progressively varying power third area. This is defined by a central part extending to both sides of the main progression meridian. In this central area each line on the progressive surface parallel to the main progression meridian substantially satisfies at every point the following equation:1/R1-1/R2=constantwherein R1 and R2 are the principal radii of the surface at the point concerned.

Abstract: A progressive lens with a continuous surface comprises three substantially constant power areas. A first such area is mathced to far vision, a second to near vision and a third, between the first and second areas, to intermediate vision. Respective progressively varying power areas lie between the first and third areas and between the third and second areas. A predetermined progress meridian passing through these substantially constant power areas may have substantially umbilical parts between the substantially constant power areas.