Abstract: Improving the optical state of a progressive addition lens along a principal line of vision through which the line-of-sight of a wearer passes by making the displacement of a position at which an optical state becomes the best to be the same as the amount of inward movement of line-of-sight, when the wearer moves his line-of-sight from the front far distance to the front near distance. An expression OI<DH may be satisfied to improve such an optical state of the progressive addition lens.

Abstract: Improving the optical state of a progressive addition lens along a principal line of vision through which the line-of-sight of a wearer passes by making the displacement of a position at which an optical state becomes the best to be the same as the amount of inward movement of line-of-sight, when the wearer moves his line-of-sight from the front far distance to the front near distance. An expression OI<DH may be satisfied to improve such an optical state of the progressive addition lens.

Abstract: A method of designing and evaluating a progressive power lens where the intersection of the wearer's line of sight, and the refractive surface of the lens is the primary line of fixation (L), the positions upon the primary line of fixation corresponding to far-field vision and near-field vision are the points (F) and (ON), respectively, and the distance of the displacement of (ON) toward the nose in the horizontal direction relative to (F) is the inward shift (OI). Upon the principal meridian curve (M) passing through (F), the point at which the profile curve (H) passing through (ON) in the horizontal direction and (M) is (DN), the displacement of (DN) towards the nose in the horizontal direction relative to (F) is the inward shift (DH), and OI<DH.

Abstract: An object is to reduce the inconvenience given to the binocular vision function when wearing and using spectacles making use of a pair of progressive power lenses having different distance dioptric power for right and left. For this reason, the present invention associates, in a pair of progressive power lenses corresponding to the right and left eyes, an average dioptric power distribution and an astigmatism distribution determined from prescribed dioptric power and a wear state of one of the progressive power lenses with an average dioptric power distribution and an astigmatism distribution determined from prescribed dioptric power and a wear state of the other progressive power lens, and thereby average dioptric power distributions and astigmatism distributions of the respective progressive power lenses are changed.

Abstract: A method provides for manufacturing progressive-power lenses in a manner in which an inventory burden of semis can be reduced. A progressive-power lens is designed by arranging a progressive-power surface on a convex surface and combining the convex surface with a concave surface so as to meet prescription values of a spectacles wearer. The method for manufacturing progressive-power lenses includes previously preparing the concave surface side as a concave surface semi group based on a predetermined classification table, selecting a most suitable semi-finished lens according to an order, designing a progressive-power surface on the convex surface side by adding the difference between cylindrical component of a most suitable concave surface semi selected based on an order and cylindrical component of the prescription values to the concave surface side so as to meet the prescription values, and finishing the lens by performing free-form processing.

Abstract: A method of designing and evaluating a progressive power lens where the intersection of the wearer's line of sight, and the refractive surface of the lens is the primary line of fixation (L), the positions upon the primary line of fixation corresponding to far-field vision and near-field vision are the points (F) and (ON), respectively, and the distance of the displacement of (ON) toward the nose in the horizontal direction relative to (F) is the inward shift (OI). Upon the principal meridian curve (M) passing through (F), the point at which the profile curve (H) passing through (ON) in the horizontal direction and (M) is (DN), the displacement of (DN) towards the nose in the horizontal direction relative to (F) is the inward shift (DH), and OI<DH.

Abstract: An object is to reduce the inconvenience given to the binocular vision function when wearing and using spectacles making use of a pair of progressive power lenses having different distance dioptric power for right and left. For this reason, the present invention associates, in a pair of progressive power lenses corresponding to the right and left eyes, an average dioptric power distribution and an astigmatism distribution determined from prescribed dioptric power and a wear state of one of the progressive power lenses with an average dioptric power distribution and an astigmatism distribution determined from prescribed dioptric power and a wear state of the other progressive power lens, and thereby average dioptric power distributions and astigmatism distributions of the respective progressive power lenses are changed.

Abstract: The present invention is made to provide a method for manufacturing progressive-power lenses in a manner in which inventory burden of semis can be reduced. The progressive-power lens is designed by arranging a progressive-power surface on a convex surface and combining the convex surface with a concave surface so as to meet prescription values of a spectacles wearer. The method for manufacturing progressive-power lenses includes the steps of: previously preparing the concave surface side as a concave surface semi group based on a predetermined classification table, selecting a most suitable semi-finished lens according to an order, designing a progressive-power surface on the convex surface side by adding the difference between cylindrical component of a most suitable concave surface semi selected based on an order and cylindrical component of the prescription values to the convex surface side so as to meet the prescription values, and finishing the lens by performing free-form processing.

Abstract: There is provided a group of bi-aspherical type progressive-power lenses for which the processing costs are reduced.

Abstract: There is provided a group of bi-aspherical type progressive-power lenses for which the processing costs are reduced.

Abstract: To provide a bi-aspherical type progressive-power lens which provides an excellent visual acuity correction for prescription values and a wide effective visual field with less distortion in wearing, by reducing a magnification difference of an image between a distance portion and a near portion of a lens, and a method of designing the same.

Abstract: To provide a bi-aspherical type progressive-power lens which provides an excellent visual acuity correction for prescription values and a wide effective visual field with less distortion in wearing, by reducing a magnification difference of an image between a distance portion and a near portion of a lens, and a method of designing the same.

Abstract: To provide a bi-aspherical type progressive-power lens which provides an excellent visual acuity correction for prescription values and a wide effective visual field with less distortion in wearing, by reducing a magnification difference of an image between a distance portion and a near portion.

Abstract: To provide a bi-aspherical type progressive-power lens which provides an excellent visual acuity correction for prescription values and a wide effective visual field with less distortion in wearing, by reducing a magnification difference of an image between a distance portion and a near portion.

Abstract: To provide a bi-aspherical type progressive-power lens which provides an excellent visual acuity correction for prescription values and a wide effective visual field with less distortion in wearing, by reducing a magnification difference of an image between a distance portion and a near portion.

Abstract: To provide a bi-aspherical type progressive-power lens which provides an excellent visual acuity correction for prescription values and a wide effective visual field with less distortion in wearing, by reducing a magnification difference of an image between a distance portion and a near portion.

Abstract: The present invention provides a progressive-power lens affording superior wear comfort, even where a shallow base curve is employed in order to make the lens lighter and thinner, which is desirable in the terms of weight and aesthetic design. In the case of a progressive-power lens for correcting hyperopia whose distance portion has a positive refractive power, such lens is designed by giving preference to minimizing transmission astigmatism at each point on the principal sight line of the distance portion, but not giving preference to making the astigmatism of the lens surface zero at each point on the principal sight line.

Abstract: A progressive power multifocal lens designed by attaching importance to an intermediate vision and a near vision in such a manner as to ensure broad intermediate vision viewing portion and near vision viewing portion and to have a well-balanced viewing zone among the distance, near and middle portions, whereby a resultant image of an object is little varied or fluctuated, especially, in lateral directions.

Abstract: A progressive power multifocal lens by which a substantially good "broad field of view" can be obtained for an eyeglass wearer without increasing time and cost required to produce the prescribed surface thereof. This progressive power multifocal lens belongs to a group of progressive power multifocal lenses designed under a certain rule in such a manner that fundamental elements such as a far vision power measuring position F and a near vision power measuring position N thereof meet a common wearing object. Further, in the case of this lens, a surface refractive power (in units of diopters) at the far vision power measuring position F is employed as a base curve (Bi). Moreover, a difference in surface refractive power between the far vision power measuring position F and the near vision power measuring position N is employed as an addition Di (in units of diopters).

Abstract: An improved ophthalmic lens for presbyopia is disclosed in which the refractive power is progressively changed to provide a natural visual target arrangement. In the .[.opthalmic.]. .Iadd.ophthalmic .Iaddend.lens, rotation of the head of a wearer for binocular lateral vision is taken into account to permit comfortable binocular lateral vision closer to vision with the naked eyes.