Abstract: A lens, system for designing, computer program for designing and a method for designing, with a computer, a progressive addition lens including a distance vision region, a near vision region, and an intermediate vision region, wherein a power gradually changes between the distance vision region and the near vision region, and wherein the progressive addition lens is based on prescription data, the method including: determining a transmission astigmatic performance parameter corresponding to a sum of a prescribed astigmatism included in the prescription data and of a predetermined amount of extra astigmatism; determining lens surface data corresponding to the determined transmission performance parameter.

Abstract: A lens, system for designing, computer program for designing and a method for designing, with a computer, a progressive addition lens including a distance vision region, a near vision region, and an intermediate vision region, wherein a power gradually changes between the distance vision region and the near vision region, and wherein the progressive addition lens is based on prescription data, the method including: determining a transmission astigmatic performance parameter corresponding to a sum of a prescribed astigmatism included in the prescription data and of a predetermined amount of extra astigmatism; determining lens surface data corresponding to the determined transmission performance parameter.

Abstract: A lens, system for designing, computer program for designing and a method for designing, with a computer, a progressive addition lens including a distance vision region, a near vision region, and an intermediate vision region, wherein a power gradually changes between the distance vision region and the near vision region, and wherein the progressive addition lens is based on prescription data, the method including: determining a transmission astigmatic performance parameter corresponding to a sum of a prescribed astigmatism included in the prescription data and of a predetermined amount of extra astigmatism; determining lens surface data corresponding to the determined transmission performance parameter.

Abstract: A progressive addition lens and the related technology, the progressive addition lens including a near portion for viewing a near distance, a distance portion for viewing a distance farther than the near distance, and an intermediate portion between the near portion and the distance portion and having a progressive refraction function, in which the transmission astigmatism is added to the near portion and the intermediate portion of the distance portion, the near portion, and the intermediate portion, and in the near portion and the intermediate portion to which the transmission astigmatism is added, the progressive addition lens further includes a portion where an amount of horizontal refractive power is greater than an amount of vertical refractive power after subtracting the refractive power for astigmatism correction.

Abstract: A progressive addition lens and the related technology, the progressive addition lens including: a near portion for viewing a near distance, a distance portion for viewing a distance farther than the near distance, and an intermediate portion between the near portion and the distance portion and having a progressive refraction function, in which the transmission astigmatism is added to the near portion and the intermediate portion of the distance portion, the near portion, and the intermediate portion, and in the near portion and the intermediate portion to which the transmission astigmatism is added, after subtracting the refractive power for astigmatism correction, the progressive addition lens further includes a portion where the amount of vertical refractive power is greater than the amount of horizontal refractive power.

Abstract: A lens, system for designing, computer program for designing and a method for designing, with a computer, a progressive addition lens including a distance vision region, a near vision region, and an intermediate vision region, wherein a power gradually changes between the distance vision region and the near vision region, and wherein the progressive addition lens is based on prescription data, the method including: determining a transmission astigmatic performance parameter corresponding to a sum of a prescribed astigmatism included in the prescription data and of a predetermined amount of extra astigmatism; determining lens surface data corresponding to the determined transmission performance parameter.

Abstract: A progressive power lens group includes a plurality of progressive power lenses including a near region for seeing an object at a near distance, a specific region for seeing an object at a far distance in relation to the near distance, and an intermediate region provided as a region between the specific region and the near region and having a power progressing from the specific region toward the near region, in which a near power at the near region is common in the plurality of progressive power lenses and a power corresponding to a predetermined common target distance which is a distance between the near distance and the far distance is provided at a predetermined part of the intermediate region.

Abstract: Provided is a technology relating to a progressive power lens including a near region for seeing an object at a near distance, a specific region for seeing an object at a far distance in relation to the near distance, and an intermediate region provided as a region between the specific region and the near region and having a power progressing from the specific region toward the near region, in which a power exceeding zero is added to a prescription power of the specific region so that a power corresponding to a predetermined target distance which is a distance between the near distance and the far distance is provided at a predetermined part of the intermediate region.

Abstract: Provided is a technology relating to a progressive power lens including a near region for seeing an object at a near distance, a specific region for seeing an object at a far distance in relation to the near distance, and an intermediate region provided as a region between the specific region and the near region and having a power progressing from the specific region toward the near region, in which a power exceeding zero is added to a prescription power of the specific region so that a power corresponding to a predetermined target distance which is a distance between the near distance and the far distance is provided at a predetermined part of the intermediate region.

Abstract: A progressive power lens group includes a plurality of progressive power lenses including a near region for seeing an object at a near distance, a specific region for seeing an object at a far distance in relation to the near distance, and an intermediate region provided as a region between the specific region and the near region and having a power progressing from the specific region toward the near region, in which a near power at the near region is common in the plurality of progressive power lenses and a power corresponding to a predetermined common target distance which is a distance between the near distance and the far distance is provided at a predetermined part of the intermediate region.

Abstract: A spectacle lens is provided belonging to a series of spectacle lenses having each of first refractive power and second refractive power in common, where a progressive region length, which is a length along a meridian within a progressive region, is shorter than a predetermined reference spectacle lens belonging to the series of spectacle lenses, and a designed maximum differential value where a normalized addition refractive power distribution in the progressive region is differentiated is caused to be close to a reference maximum differential value where a normalized addition refractive power distribution in the progressive region of the reference spectacle lens is differentiated.

Abstract: A spectacle lens is provided belonging to a series of spectacle lenses having each of first refractive power and second refractive power in common, where a progressive region length, which is a length along a meridian within a progressive region, is shorter than a predetermined reference spectacle lens belonging to the series of spectacle lenses, and a designed maximum differential value where a normalized addition refractive power distribution in the progressive region is differentiated is caused to be close to a reference maximum differential value where a normalized addition refractive power distribution in the progressive region of the reference spectacle lens is differentiated.

Abstract: A progressive power lens whose distance viewing vertex power is a negative value and in which a surface refractive power Pf.sub.m in the main meridional plane in a distance viewing portion is larger than a surface refractive power Pf.sub.s in a plane perpendicular to the main meridional plane (Pf.sub.m >Pf.sub.s). A surface refractive power Pn.sub.m in a section in the main meridional plane in a near viewing portion is smaller than the surface refractive power Pn.sub.s in a plane perpendicular to the main meridional plane (Pn.sub.m <Pn.sub.s).

Abstract: A pupil conjugate-coupling device in a projecting optical system includes a first projection lens system which forms an intermediate image of an image indicating element, a second projection lens system which projects the intermediate image onto a screen, said first and second projection lens systems having optical axes intersecting at a predetermined angle, and an optical element having structural periodicity positioned between the first and second projection lens systems. The optical element has a positive power and a prism function for deflecting a bundle of rays transmitted through the first projection lens system towards the optical axis of the second projection lens system to thereby couple pupils of the first and second projection lens systems. The optical element is deviated from an intermediate image forming position by a predetermined offset in the optical axis direction thereof.

Abstract: In an aspherical spectacle lens having a negative degree and an aspherical surface of rotational symmetry located on an object side, a surface power of the aspherical surface of rotational symmetry at a center portion located on an axis of rotational symmetry is substantially 0 diopter, and the aspherical surface of rotational symmetry is of an apparent convex shape.