摘要:
A monofocal ophthalmic lens having a front and a rear surface, each of which is aspherical, of which at least one surface has identical radii of principle curvature in the apex. The average surface refracting power of at least one of the front and rear surfaces is defined by the formula: Bf=(n−1)/2*(1/R1+1/R2) wherein n: is the refractive index of the lens medium, R1: is the radius of principle curvature 2 in a point of at least one of the front and rear surfaces in a first principle plane, and R2: is the radius of principle curvature 2 in the point of the at least one in the front and rear surfaces in a second principle plane, and wherein the average surface refracting power of points on the at least one of the front and rear surfaces is the function of the distance h at constant azimuthal angle of &OHgr; of each point from the apex, and the function includes an extreme value and/or a value 0.
摘要:
A progressive ophthalmic lens including at least one distant vision zone in which the power is suitable for distant viewing, at least one near vision zone in which the power is suitable for near viewing, and at least one progression zone in which the power varies continuously from the power of the distant vision zone to the power of the near vision zone along a principal line, at least one surface of the ophthalmic lens contributing to the power variation. A surface astigmatism of the at least one of surface of the ophthalmic lens contributing to the power variation along at least one horizontal intersection, represented by an intersection of the ophthalmic lens and a horizontal plane where y=const, has a local maximum value located at a distance of not more than 4 mm from the principal line, and at least one local minimum value which does not lie on the principal line and is located at a greater distance from the principal line than the local maximum value.
摘要:
A double progressive spectacle lens having a prefabricated progressive surface and a second progressive surface for correcting a spherical ametropia or a cylindrical ametropia, in which the surface properties of the progressive surface in the vicinity of the principal line of sight are asymmetric, the asymmetry being determined by the symmetry factor SA, which is determined in relation to the level A by the ratio of the smaller to the larger horizontal distance between the principal line of sight and the location at which the surface astigmatism in the horizontal section reaches the value A [dpt].
摘要:
A unifocal spectacle lens with an aspheric and/or atoric surface, or a progressive spectacle lens, in which the unifocal spectacle lens or the progressive spectacle lens has small higher order aberrations.
摘要:
A method for manufacturing a spectacle lens, in which at first a semi-finished uncut spectacle lens (hereinafter referred to as a blank) is produced, i.e. a spectacle lens having merely one finished optical surface (hereinafter described as base surface); subsequently a prescription-optimized surface is computed according to the data of a spectacle lens prescription; and then the prescription-optimized surface is finished according to the computed data. The invention is characterized by the following method steps: after the production of the semi-finished spectacle lens the base surface is measured; the prescription-optimized surface is computed and finished taking into account not only the individual data of the spectacle prescription, but also the actual shape of the base surface.
摘要:
A method for representing and optimizing a double-progressive spectacle lens is characterized by the following steps: selecting a suitable coordinate system K2 for the representation of a back surface; selecting a suitable grid G for the representation of a spline of the back surface of a starting lens to be optimized in a coordinate system K2; assigning sagittal height data of the back surface to a spline (back surface spline); defining a position of a center of rotation of an eye; computing principal rays from the center of rotation of the eye through the starting lens at grid points of G; computing a length of a distance between points of penetration of a thus computed principal ray through a front surface and the back surface (oblique thickness); assigning data of the oblique thickness (thickness spline) to a spline; selecting a set of assessment positions at which an optical quality is computed for a target function; suitably selecting particular optical and geometrical stipulations which ideally should be satisfied at the assessment positions; defining the target function as a deviation of the quality of an actual spectacle lens from ideal values; starting the optimization; evaluating at each one of optimization steps the optical properties in a wearing position at the assessment points by means of surface properties to be computed and actual principal ray data; ending the optimization when the target function is below a particular value, or after a specifiable maximum number of optimization steps.
摘要:
The present description refers to a series of progressive lenses, wherein the lenses present a different surface power in the distance-vision part and/or a different increase of the surface power from the distance-vision part towards the near-vision part (termed addition Add hereinafter), and whereof each comprises a front surface having a continuously varying surface power which increases from the respective value BK �dpt!, which is suitable for distance vision, at the point having the coordinates x=0 mm, y=8 mm in the lower region of the distance-vision part along a wound line (primary line), which coincides approximately with the primary line of view, with eyes dropped, towards a value suitable for near vision in the upper region of the near-vision part, which value is greater than the value of the surface power BK in the lower region of the distance-vision part by the value ADD �dpt! of the addition, and having a surface, in particular the surface on the concave side, which has a spherical shape or an aspherical shape, respectively. The present invention is characterized by the aspects that for the maximum height y of the line on which the surface astigmatism is 0.5 dpt and which defines the lower limit of the region suitable for clear vision on either side of the primary line at a distance of 25 mm, applies: y=f(Add,BK)=b(BK)+a/Add*1000) b(BK)=a.sub.0 +a.sub.1 *BK+a.sub.2 *BK.sup.2 and that for the coefficients on the nose side and the temporal side of the primary line applies: ______________________________________ nose side temporal side ______________________________________ a -8.5 .+-. 20% -7.5 .+-. 20% a.sub.0 18...19 mm 19...20 a.sub.1 -3580 .+-. 29% mm.sup.2 -4520 .+-. 20% mm.sup.2 a.sub.2 390 000 .+-. 20% mm.sup.3 480 000 .+-. 20% mm.sup.3. ______________________________________
摘要:
A method of optimizing a progressive lens is described. This invention is characterized by the following steps: selecting a preset progressive lens having a preset object distance function A1(x,y), selecting an object distance function A2(x=x0,y) along the main line of vision of the preset progressive lens for a lens that is to be derived, locating the map U:y→y′ along the main line of vision, such that the value y′ for which the following holds is calculated for each value of y: A1(x=x0,y)=A2(x=x0,y′), calculating the setpoint values S(x,y) at S(x,y′)=S(x,U(y)).
摘要:
A progressive spectacle lens having two aspherical and in particular progressive surfaces, i.e. surfaces contributing to the rise in the effect (addition Add.) from the distance vision portion to the near vision portion, in which the sagittal heights zi=zi(x,y) of at least one (i) progressive surface (i=1,2) are chosen such that the sagittal height z of this respective surface at the edge of the spectacle lens given by yi=fi1(x) for y≧0 and yi=fi2(x) for y
摘要:
A unifocal spectacle lens with an aspheric and/or atoric surface, or a progressive spectacle lens, in which the unifocal spectacle lens or the progressive spectacle lens has small higher order aberrations.