An eye-strain reducing lens is characterized by an x-y-z coordinate system, and includes a distance-vision region, having a negative distance-vision optical power, configured to refract a light ray, directed by a source at a distance-vision region point at a distance-vision x-distance from a center of the coordinate system, to propagate to an eye-center-representative location; and a near-vision region, having a near-vision optical power that matches the distance-vision optical power within 0.5 D, configured to refract a light ray, directed by the source at a near-vision region point at a near-vision x-distance from the center of the coordinate system, to propagate to an x-z location of the eye-center representative location at a corresponding y height; wherein the near-vision x-distance is smaller than the distance-vision x-distance.

A convergence-reducing lens, wherein a central normal defines a z-axis, and a central region defines an x-y plane, together defining an x-y-z coordinate system, the convergence-reducing lens comprising a distance-vision region with a negative distance-vision optical power, having a distance-vision front surface with a center of distance-vision front curvature, and a distance-vision rear surface with a center of distance-vision rear curvature; and a near-vision region with an optical power within 0.5D of the distance-vision optical power, having a near-vision front surface with a center of near-vision front curvature, and a near-vision rear surface with a center of near-vision rear curvature; wherein at least one of an x-coordinate of the center of near-vision front curvature is nasal relative to an x-coordinate of the center of distance-vision front curvature, and an x-coordinate of the center of near-vision rear curvature is temporal relative to an x-coordinate of the center of distance-vision rear curvature.

An off-axis curvature center lens is characterized by an x-y-z coordinate system of the convergence-reducing lens, the off-axis curvature lens comprising a distance-vision region with a non-negative distance-vision optical power, having a front distance-vision surface with a center of front distance-vision curvature, and a rear distance-vision surface with a center of rear distance-vision curvature; and a near-vision region with an optical power within 0.5D of the distance-vision optical power, having a front near-vision surface with a center of front near-vision curvature, and a rear near-vision surface with a center of rear near-vision curvature; wherein at least one of an x-coordinate of the center of front near-vision curvature is nasal relative to an x-coordinate of the center of front distance-vision curvature, and an x-coordinate of the center of rear near-vision curvature is temporal relative to an x-coordinate of the center of rear distance-vision curvature.

A pair of spectacle lenses includes: a first refractive portion; a second refractive portion whose refractive power is stronger than the first's; and a progressive power portion in which a refractive power changes progressively from the first to the second refractive portion, first refractive powers of a left and right of the lenses being different, progressive power portions lengths of the left and right of the lenses are different and changing rates of additions of the left and right of the lenses are different in accordance with a shift between left and right visual lines so that a difference between addition effects acting on the wearer's eyes is reduced when the left and right visual lines shift with respect to each other depending on the first refractive powers of the left and the right of the lenses being different where the wearer views an object through the lenses.

A progressive addition lens design method includes adjusting a lens surface shape to bring a difference between a first state when an object at a first location in a wearer's front and on the wearer's medial plane is visually recognized and a second state when an object at a second location positioned on the first location side in the horizontal direction at a constant height in the vertical direction is visually recognized in a plane parallel to a frontal plane and includes the first location at the time the lens is worn closer to a difference between a third state when an object at the first location is visually recognized and a fourth state when an object at the second location is visually recognized at the time a reference single focal lens corresponding to the progressive addition lens is worn or at the time equivalent to a naked eye.

A progressive addition lens includes a portion having a power for viewing a near field, a portion having a power for viewing a distance field further than the near field, and an portion connecting the distance portion and the near portion. The progressive addition lens includes an aspherical object-side surface and an aspherical eyeball-side surface and is formed in rotational symmetry with respect to a center of design of the progressive addition lens. The object-side surface includes a first stable region formed in rotational symmetry with respect to the center of design and including the center of design, and an aspherical region arranged outside of the first stable region to contact the first stable region and formed in rotational symmetry with respect to the center of design. A PV value (Peak to Valley) of a mean surface refractive power in the first stable region is 0.12 D or less.

A progressive multifocal contact lens and producing method thereof are provided. The progressive multifocal contact lens includes a first optical region of a front optical surface and a second optical region of a back optical surface. The first optical region includes a center zone, an outer zone and an intermediate zone connected between the center zone and outer zone where the center zone and outer zone are selected from a distance vision power and a near vision power and the intermediate zone is configured to adjust the optical power of the distance vision power and the near vision power so that the optical power or add power of the first optical region on the front optical surface forms a normal cumulative distribution function.

Method for defining one face of an ophthalmic lens, having a surface formed by superposing a Fresnel layer and a continuous surface referred to as the carrier. Also disclosed is an ophthalmic lens comprising such a face. The method allows a Fresnel layer to be defined that compensates for geometric effects induced by a variation in the curvature of the carrier on the light incident on the face of an ophthalmic lens. This method is particularly useful when the curvature of the face of the ophthalmic lens is adapted to facilitate fitting it into a spectacle frame.

A progressive ophthalmic spectacle lens (10) capable of correcting a wearer's ophthalmic vision and having a back surface (BS) and a front surface (FS), said lens comprising a light guide optical element arranged to output a supplementary image (SI) to the wearer through an exit surface (ES) of said light guide optical element, where the exit surface (ES), the back surface (BS) and an optical material located between said exit surface (ES) and said back surface (BS) form an optical device (OD) and wherein said optical device (OD) comprises an area of stabilized optical power.

Progressive power lens including: object side surface; eyeball side surface; and at least a near portion having a power for near vision, wherein object side surface includes power change in vertical direction of lens having progressive refractive power function, eyeball side surface includes power change in horizontal direction of lens having progressive refractive power function, when surface refractive power in the horizontal direction is defined as DHn and surface refractive power in vertical direction is defined as DVn in near power measurement point N in object side surface, relational expression of DHn<DVn is fulfilled, and near portion of eyeball side surface has a shaped part wherein signs of positive and negative of surface refractive power in vertical direction of lens and surface refractive power in horizontal direction of lens are opposite to each other.