TH30320B - Progressive multi-focus lens - Google Patents

Abstract

Multifocal progressive lenses, which provide an exceptionally wide field of vision, can be achieved for wearers without the added time and expense required to manufacture custom lens surfaces. These multifocal progressive lenses belong to the group of multifocal progressive lenses designed under a rule such that basic elements, such as the distance (F) and near (N) temples of the lens, fit into a typical object being worn. Next, in the case of this lens, the refractive power of the surface (in diopters) at the distance (F) temple is used as the basis (Bi). Furthermore, the difference in refractive power between the distance (F) and near (N) temples is used as the addition (Di) (in diopters). Moreover, W(Di,Bi) represents the width of the region where the average refractive power increase of the surface along the horizontal cross-section is achieved. The projection below the near power measurement position (N) is not less than Di/2 in such a case, when two custom progressive multifocal lenses, whose addition is Da and the base curves are B1 and B2, respectively, are selected from a group of progressive multifocal lenses, the following relationship exists for B1 > bB2: W(Da, B1) > W(Da, B2).

Claims (5)

1. Multi-focus progressive lens It has a basic component, which consists of the telescopic position (F) and telescopic position (N), and is part of a group of multifocal progressive lenses designed under the hood. pre-defined law in such a way that Basic components are generally intended for wear. where the refractive power of the surface (in diopters) at the telescopic power measurement position (F) is used as the fundamental curve (Bi), where the difference in surface refractive power between the telescopic power measurement positions ( F) , and the near-field power measurement position (N) is used as an increment (Di (in diopters)) where a custom selector of a multifocal progressive lens is used. Two lenses where its addition is Da and fundamental curves are B1 and B2, respectively, from a group of multifocal progressive lenses. The following relationship exists for (B1>B2: W(Da,B1)>W(Da,B2) where W(Da,Bi)(i=1 or 2) is the width of the region where the value of The average increase in louse force of the surface along the horizontal cross-section The lower protrusion near the near-field measuring position (N) is not less than Di/2. 2. Multifocal progressive lens according to claim 1, where a single arc is used that goes straight to at least both the telephoto end (F) and the measuring position. Near field of vision (N) is the main alignment line, horizontal deflection H of the custom point (P) on the main capture line to the wearer's nose. With respect to the far-field power measurement position (F) is determined by; H= K.Dp/Di, where K is a custom constant that follows the inequality 1.1 <=K<=5.0; Dp is the refractive force of the face increasing at the custom point (P). ; and Di is the addition. 3. Multifocal progressive lens according to claim 1, in which the visualization conditions change according to the horizontal cross-section curve intersecting the main capture line. At the custom point (P) occurs in such a way that in which the main capture line is not deflected horizontally. From the horizontal location of the telescopic measuring position (F), the visual condition is symmetrical with respect to the plane with a defined point (P) and perpendicular to the cross-sectional curve. and acts as a plane of symmetry of the mirror. in such a way that In another section where the main capture line is diverted horizontally to the wearer's nose. From the horizontal position of the telescopic measuring position (F), changing the field of vision according to the visual cross-section along a cross section along another human line extending from the designated point (p) to the wearer's ear. 4. Multifocal progressive lens according to claim 1, where the Di increase is in the range from 0.75 diopters to 3.00 diopters , where when the lens po Two self-defined multifocal progressive lenses , whose additions are Da and Db respectively, and the fundamental curves are identical to each other. Selected from a group of multifocal progressive lenses, the following relationship is effective for increasing W(Da,X) Db/Da (occurring X=1.00 diopter), where W(Di,X (mm) (i=a or b) represents, the width of the region where the value of the horizontal arc cross-section tolerance passing directly to the near field of view (N) is no more than x 5. Multi-focus progressive lens according to claim 1, where a custom point (P) on the main capture line segment, in addition to the telescopic measurement position (F ) and the near-field power measurement position (N) p has two different primary curvatures.