Progressive spectacle lens having a variable refractive index and method for the design and production thereof
A progressive spectacle lens has a front face and a rear face and a uniform substrate with a locally varying refractive index. The front face and/or the rear face of the substrate is formed as a free-form surface and carries only functional coatings, if any. The refractive index varies (a) only in a first spatial dimension and in a second spatial dimension and is constant in a third spatial dimension, a distribution of the refractive being neither point-symmetrical nor axis symmetrical, or (b) in a first spatial dimension and in a second spatial dimension and in a third spatial dimension, a distribution of the refractive index being neither point-symmetrical nor axis symmetrical, or (c) in a first spatial dimension and in a second spatial dimension and in a third spatial dimension, a distribution of the refractive index not being point-symmetrical or axis symmetrical at all.
1. A product comprising:
(i) a progressive power spectacle lens, or (ii) a representation of the progressive power spectacle lens having instructions for the production thereof using an additive method, the representation being stored on a non-transitory data medium in the form of computer-readable data, or (iii) the non-transitory data medium with a virtual representation of the progressive power spectacle lens in the form of the computer-readable data having instructions for the production thereof using an additive method, or (iv) the representation of the progressive power spectacle lens in the form of the computer-readable data signal having instructions for the production thereof using an additive method, wherein the progressive power spectacle lens has:
a substrate having no individual parts forming discrete interfaces and having a spatially varying refractive index; and
the substrate having a front surface and a back surface,
wherein, during use as intended, the front surface and the back surface of the substrate either form the outer surfaces of the progressive power spectacle lens, or
one of the front surface or the back surface forms one of the outer surfaces, wherein a functional coating is provided on the other of the front surface or the back surface, wherein the functional coating does not contribute or at each point contributes less than 0.004 dpt to a spherical equivalent of a dioptric power of the progressive power spectacle lens and forms the other of the outer surfaces, or
the outer surfaces are formed by the functional coatings provided on each of the front surface and back surface of the substrate, wherein the functional coatings do not contribute or at each point contribute less than 0.004 dpt to the spherical equivalent of the dioptric power of the progressive power spectacle lens,
wherein at least one of the front surface or the back surface of the substrate is configured as a freeform surface, and
wherein
(a) the refractive index varies only in a first spatial dimension and in a second spatial dimension and is constant in a third spatial dimension, wherein a distribution of the refractive index in the first spatial dimension and the second spatial dimension has neither point symmetry nor axial symmetry.
2. A product comprising:
(i) a progressive power spectacle lens, or (ii) a representation of the progressive power spectacle lens having instructions for the production thereof using an additive method, the representation being stored on a non-transitory data medium in the form of computer-readable data, or (iii) the non-transitory data medium with a virtual representation of the progressive power spectacle lens in the form of the computer-readable data having instructions for the production thereof using an additive method, wherein the progressive power spectacle lens has:
a substrate having no individual layers and having a front surface and a back surface, and
at least one of a front surface coating, including one or more individual layers, on the front surface of the substrate, or a back surface coating, including one or more individual layers, on the back surface of the substrate,
wherein the substrate has a spatially varying refractive index, wherein
the at least one of the front surface or the back surface of the substrate is configured as a freeform surface, and wherein the freeform surface is configured as a progressive surface,
wherein
a difference between a spherical equivalent measured at each point on the front surface of the progressive power spectacle lens with the at least one of the front surface coating or the back surface coating and the spherical equivalent measured at each corresponding point on the front surface of a comparison progressive power spectacle lens without front surface coating and without back surface coating but with an identical substrate is less than 0.004 dpt,
wherein
(a) the refractive index varies only in a first spatial dimension and in a second spatial dimension and is constant in a third spatial dimension, wherein a distribution of the refractive index in the first spatial dimension and the second spatial dimension has neither point symmetry nor axial symmetry, and wherein
the front surface coating forms a first outer surface of the spectacle lens and the back surface of the substrate forms a second outer surfaces of the spectacle lens, or
the back surface coating forms a first outer surface of the spectacle lens and the front surface of the substrate forms a second outer surface of the spectacle lens, or
the outer surfaces of the spectacle lens are formed by the front surface coating and the back surface coating provided on each of the front surface and back surface of the substrate.