摘要:
An ophthalmic lens in which one surface is provided with at least one region, in which the refracting power is practically constant except for aspherical corrections, and at least one transition region which is adjacent to the region having practically constant surface refracting power, and in which the surface refracting power increases or decreases continuously, and the other surface is provided with an astigmatic effect. The orientation of the surface having an astigmatic effect relative to the surface having continuous refracting power change is dependent on the position of the axis of the astigmatism of the eye. The surface having an astigmatic effect deviates from the toric shape and is independent of the orientation of the surface relative to the surface having continuous refracting power change which is a surface optimized for the axial position of 0.degree..
摘要:
A series of progressive ophthalmic lenses, each having a varying surface power in a distance part and/or a varying increase in surface power from a distance part to a near part, includes a front surface having a continuously varying surface power and an eye-facing surface, principal sections of which have varying powers and at least one of which deviates from a circular form. The lenses have astigmatic power and are distinguished by a deviation (dz) between an apex circle and a sagitta of each principal section, as given by the equation:dz=a.sub.j *r.sup.2 +b.sub.j *r.sup.4with coefficients.vertline.a.sub.j .vertline..ltoreq.2*10.sup.-4 mm.sup.-1.vertline.b.sub.j .vertline..ltoreq.1*10.sup.-6 mm.sup.-3and where coefficients a.sub.j2 and b.sub.j2 are yielded by the following functionals:a.sub.j =f.sub.j1 (sph,zyl)=a.sub.j1 (sph)+b.sub.j1 (sph)*zylb.sub.j =f.sub.j2 (sph,zyl)=a.sub.j2 (sph)+b.sub.j2 (sph)*zylwith coefficients a.sub.j2 and b.sub.j2 being a function of a second order.
摘要:
An ophthalmic lens having a front and an eye-facing boundary surface and a varying refractive index, which contributes to the correction of aberrations. The ophthalmic lens is distinguished by having at least one system of surfaces at given level (n(x,y,z)=const.) with a constant refractive index, which are spaced the same distance at all points in the direction of their surface normals (parallel surfaces), and which, respectively their extension, intersect the axis connecting the lens apexes of the front surface and the eye-facing surface.
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:
An ophthalmic lens for use in the correction of astigmation, wherein in order to reduce the critical thickness and/or the variation of the edge thickness along the circumference of the lens, the refractive index changes at least along the critical main section in such a manner that at least part of the cylindrical correction is attained by the refractive index variation.
摘要:
A progressive ophthalmic lens comprising a distance portion, the refractive power of which being designed for distance vision, a reading portion, the refractive power of which being designed for near vision, and an intermediate portion, in which the refractive power along the main line of vision at least partially increases continuously from the refractive power of the distance portion to the reading portion. A refractive index of the lens material varies along the main line of vision at least in the intermediate portion so as to at least partially contribute to the increase in refractive power and correction of aberrations.
摘要:
A multifocal lens is described with a main lens designed for distance vision and a segment designed for near vision.The lens in accordance with the present invention is characterized by the fact that one surface of the segment consists of the progression area and the reading portion of a progressive surface.In an advantageous further development the progressive surface whose progression area and reading portion form one surface of the segment is designed in such a way that its surface astigmatism is concentrated essentially in the distance portion.
摘要:
In the disclosed lens, one lens surface is divided into an upper distance-vision portion FT, a lower near-vision portion NT, and a varying or transitional region PB between the two other portions. In the upper distance-vision portion, the surface contains a far reference point B.sub.F and exhibits predetermined average distance-vision surface refractive powers D.sub.F. The lower near-vision portion contains a near-vision reference point B.sub.N and has predetermined average near-vision surface refractive powers D.sub.N. The transitional region exhibits average surface refractive powers D.sub.P which effect a smooth transition from the distance-vision portion to the near-vision portion. The surface is divided into a temporal portion and a nasal portion by a principal meridian M which forms an umbilical line.
摘要:
A uniform strength ophthalmic lens having a gradient refractive index changing rotational-symmetrically about the optical axis in which the curvature course of at least one of the two surfaces of the ophthalmic lens is selected without consideration of correction of aberration so that the critical thickness of the ophthalmic lens does not exceed a specific value and that the gradient refractive index is change rotational-symmetrically about the optical axis so as to correct the aberration. In this manner, a significant reduction of the critical thickness of the opthalmic lens, i.e., the center thickness is a positive lens and peripheral thickness in a negative lens, is achieved while providing an ophthalmic lens having good image-forming properties.
摘要:
A progressive power ophthalmic lens having at least one surface contributing to an increase in power from a distant portion via a progressive zone to a reading portion, radii of curvature of horizontal section curves of the at least one surface contributing to an increase in power and having horizontal planes as a function of the distance from the main meridian decrease in a front surface in the region of the main meridian in the distant portion and increase in the rear surface in the distant portion and decrease in the reading portion, and the course of change of the curvature .DELTA.rh-rh(x,y)-rh (0,y) reverses with increasing distance x from the main meridian.