Hoya Corporation

Hoya Lens Corporation

Kabushiki Kaisha Hoya Lens

Akira Kitani

Yoshihiro Kikuchi

Takashi Hatanaka

Hua Qi

Tsuyoshi Saigo

Eichin Wolfgang

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&#x3c;DH may be satisfied to improve such an optical state of the progressive addition lens.

Progressive power lens, method of designing progressive power lens and method of evaluating progressive power lens

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&#x3c;DH.

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.

Pair of progressive power lens and method for designing same

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.

Progressive power lens manufacturing method and progressive power lens

There is provided a group of bi-aspherical type progressive-power lenses for which the processing costs are reduced. In a bi-aspherical type progressive-power lens(es), the relationships DHf+DHn&#x3c;DVf+DVn and DHn&#x3c;DVn or further, DVn&#x2212;DVf&#x3e;ADD/2 and DHn&#x2212;DHf&#x3c;ADD/2 are satisfied; DHf and DVf are designated respectively as a surface refractive power in a horizontal direction and a surface refractive power in a vertical direction at a far vision power measurement position Fon a first refractive surface that acts as an object-side surface; with DHn and DVn are designated respectively as a surface refractive power in a horizontal direction and a surface refractive power in a vertical direction at a near vision power measurement position Non the first refractive surface; a surface astigmatism component at Fand Nof the first refractive surface is canceled by a second refractive surface of the eye-side surface; and the first and second refractive surfaces are combined to provide a far vision power (Df) and an addition (ADD) on the basis of a prescription; wherein the same first refractive surface is used for at least two or more kinds of different addition power.

Method for designing group of bi-aspherical type progressive-power lenses, and group of bi-aspherical type progressive-power lenses

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. A progressive action of a progressive-power lens is divided in the vertical direction and the horizontal direction of the lens and then an optimal sharing ratio between the front and rear two surfaces of the object side and the eyeball side is set in each direction to configure one bi-aspherical type progressive-power lens, a sharing ratio of a progressive action in the horizontal direction of a rear surface (eyeball side surface) is set higher so that an advantage of increasing the visual field in the horizontal direction can be obtained, a sharing ratio of a progressive action in the vertical direction of a front surface (object side surface) is set higher so that a disadvantage of increasing an eyeball turning angle between the distance and near portions in the vertical direction can be restrained, also a wide effective visual field with less distortion in wearing can be provided by reducing a magnification difference of an image between the distance portion and the near portion on the progressive-power lens, further making it possible to obtain a bi-aspherical type progressive-power lens capable of reducing a machining time and cost by making it possible to machine only the surface of an eyeball side as a bilaterally asymmetrical curved surface coping with a convergence action of an eye in near vision after receiving an order, by using 'bilaterally symmetrical semi-finished product' as an object side surface of the progressive refractive power lens.

Bi-aspherical type progressive-power lens and method of designing the same

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. The lens is characterized in that when on a first refractive surface being an object side surface, a surface refractive power in a horizontal direction and a surface refractive power in a vertical direction, at a far vision diopter measurement position F, are DHf and DVf respectively, and on the first refractive surface, a surface refractive power in a horizontal direction and a surface refractive power in a vertical direction, at a near vision diopter measurement position N, are DHn and DVn respectively, relational equations, DHf+DHn&#x3c;Dvf+DVn, and DHn&#x3c;DVn are satisfied, and surface astigmatism components at Fand Nof the first refractive surface are cancelled by the second refractive surface being an eyeball side surface so that the first and second refractive surfaces together provide a far vision diopter (Df) and an addition diopter (ADD) based on prescription values.

Bi-aspherical type progressive-power lens

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. The lens is characterized in that when on a first refractive surface being an object side surface, a surface refractive power in a horizontal direction and a surface refractive power in a vertical direction, at a far vision diopter measurement position F, are DHf and DVf respectively, and on the first refractive surface, a surface refractive power in a horizontal direction and a surface refractive power in a vertical direction, at a near vision diopter measurement position N, are DHn and DVn respectively, relational equations,, andare satisfied, and surface astigmatism components at Fand Nof the first refractive surface are cancelled by the second refractive surface being an eyeball side surface so that the first and second refractive surfaces together provide a far vision diopter (Df) and an addition diopter (ADD) based on prescription values.

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. On the other hand, in the case of a myopia corrective progressive-power lens for correcting myopia whose distance portion has a negative refractive power, such lens is designed by giving preference to minimizing transmission average refractive power error at each point on the principal sight line of the distance portion, but not to making the astigmatism of lens surface zero at each point on the principal sight line.

Progressive-power lens and design process for same

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.

Progressive power multifocal lens

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). Furthermore, let W(Di, Bi) denote a width of a region in which values of a surface average additional refractive power along a horizontal section line extending below the near vision power measuring position N are not less than Di/2. In such a case, when arbitrary two progressive power multifocal lenses, whose additions are Da and base curves are B1 and B2, respectively, are extracted or selected from the group of the progressive power multifocal lenses, the following relation holds for B1&gt;B2:

A progressive power omnifocal lens (1, 5) for constituting spectacles having for vision and near vision focuses, having an area in which the refacting power progressively changes (successively increases) from upper to lower positions in the vicinity of the horizontal center of the lens; and a main fixation line (4, 6) generally called an 'umbilical meridian' formed in the progressive-change area, in which the degree of astigmatism along the main fixation line is substantially zero, and the main fixation line is gradually displaced toward the nose in accordance with the convergence of the eyes as it extends from an upper position to a lower position. The disposition of the main fixation line displaced toward the nose is varied depending upon the addition of the lens in such a manner that it is shifted upward as the addition of the lens is reduced, thereby optimizing the performance of the lens for a particular user.

Progressive power omnifocal lens

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 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.

Progressive power ophthalmic lens

A method for determining the optimum thickness of an ophthalmic lens comprises the steps of applying data indicative of the kind of a lens suitable for a spectacle wearer and the contents of a prescription as inputs to a computer, executing necessary computation by the computer according to a predetermined program on the basis of the various input data thereby drawing a map of an equi-thickness line group of the ophthalmic lens on the basis of the result of computation, and placing a spectacle frame at a predetermined position on the map of the equi-thickness line group to find out the outermost equi-thickness line within the extent of the frame.

Method for determining optimum thickness of ophthalmic lens

A progressive multi-focal lens is provided of the type having a distant viewing zone, a near viewing zone, and a progressive zone therebetween. The surface refractive power increases vertically from an upper portion of the lens to a lower portion as the line of sight scans from a distant view to a near view. Side zones are provided beside the progressive and near viewing zones. The side zones are spheric surfaces, with a dioptric refractive power in accordance with one embodiment being the arithmetic mean value of the refractive power of the near and distant viewing zones. This eliminates astigmatism problems in the side areas and permits normal side sight.

Growing community of inventors

Tokyo, Japan

Akira Kitani