Spectacle lens having a diffraction structure for light

A spectacle lens for an observer, the spectacle lens comprising:

• a body having at least one diffraction structure extending along a body surface,
• wherein a refractive index n(x, y) of the at least one diffraction structure is spatially modulated in dependence on a location on the body surface,
• wherein the spatial modulation of the refractive index n(x,y) in the body is continuous and the diffraction structure is configured to convert a spherical light wave which originates from a point on an object surface selected from a free-form surface, a plane, a curved surface, or a bent surface, the object surface being arranged on a side of the spectacle lens facing away from the observer, into a light wave which projects an image of the point on the object surface onto an image point lying in an image surface that is optically conjugate to the object surface,
• wherein the spatial modulation of the refractive index n(x,y) is continuous over a contiguous area B of the body surface, for the diameter D of which, defined as the supremum of a metric distance d(x,y) between two arbitrary points x, y arranged in the area of the body surface, with
• D:=sup{d(x, y):
• x, y ∈ B},
• the following applies:
• D≥10 mm,
• wherein the at least one diffraction structure in the area B is configured to convert the spherical light wave which originates from the point on the object surface into the light wave which projects the image of the point on the object surface onto the image point lying on the image surface that is optically conjugate to the object surface.

A method for determining the design of a spectacle lens with a body, the method comprising:

• specifying a geometry and an object surface from the group including a free-form surface, a plane, a curved surface, or a bent surface, the object surface being arranged on a side of the spectacle lens facing away from the observer;
• specifying an optical transfer function for the spectacle lens;
• calculating a phase object which directs the light incident on a side of the spectacle lens facing away from the observer at an angle of incidence α to a surface normal {right arrow over (n)} of the of the spectacle lens front surface in a direction dependent on the wavelength λ of the light and on the angle of incidence α of the light for the specified optical transfer function and the specified geometry,
• wherein the phase object contains at least one diffraction structure, which is made to extend in the body on a body surface and, when observing an object surface, can be passed through by a line of sight ray that corresponds to a viewing direction of an eye of the observer having a center of rotation of the eye and a pupil center and extends through the center of rotation of the eye and the pupil center as well as the point on the object surface;
• forming the at least one diffraction structure by a spatial modulation of the refractive index n(x, y) that is dependent on the location (x, y) in the body surface passed through by the viewing direction,
• wherein the spatial modulation of the refractive index n(x, y) in the body is continuous and the diffraction structure converts a spherical light wave which originates from a point on an object surface into a light wave which projects an image of the point on the object surface onto an image point lying in an image surface that is optically conjugate to the object surface,
• wherein the diffraction structure converts a spherical light wave which originates from a point on the object surface that is passed through by the viewing direction into a light wave, running along the viewing direction, which projects an image of the point on the object surface onto an image point in the eye of the observer lying in an image surface that is optically conjugate to the object surface,
• wherein the spatial modulation of the refractive index n(x, y) is continuous over a contiguous area B of the body surface, for the diameter D of which, defined as the supremum of the metric distance d(x,y) between two arbitrary points x, y arranged in the area of the body surface, with
• D:=sup{d(x, y):
• x, y ∈ B},
• the following applies:
• D≥10 mm
• or
• D≥20 mm,
• and wherein the diffraction structure in the area B converts a spherical light wave which originates from a point on an object surface into a light wave which projects an image of the point on the object surface onto an image point lying in an image surface that is optically conjugate to the object surface.