Progressive spectacle lens for seeing objects at a large or average distance
View Patent ↗A spectacle lens having in a first see-through region a power suitable for distant viewing in a wearing position, and in a second see-through region a power suitable for medium-distance viewing, i.e. for distances of about 1 meter and more, in a wearing position, and in which the power continuously increases from the first see-through region along a plane or winding principal line to the second see-through region. The spectacle lens has the following features: the power increases not only from the first see-through region to the second see-through region, but also continuously to beyond the second see-through region to a lower edge of the spectacle lens; and a region of clear vision, i.e. a region in which a residual astigmatism of a system spectacle-lens/eye does not exceed 0.5 dpt, narrows below the first see-through region towards the lower edge of the spectacle lens to have a funnel-shaped configuration, i.e. without any constriction.
1. Spectacle lens,
having in a first see-through region a power suitable for viewing at a far distance in a wearing position; and
having in a second see-through region a power suitable for viewing at medium distances, i.e. for distances of about one meter and more in a wearing position; and
in which the power continually increases from the first see-through region along a plane or winding principal line to the second see-through region;
with the following features:
the power increases not only from the first see-through region to the second see-through region, but also continuously beyond the second see-through region to a lower edge of the spectacle lens; and
a region of clear vision, i.e. a region in which a residual astigmatism of a system-spectacle lens eye does not exceed 0.5 dpt, narrows below the first see-through region towards the lower edge of the spectacle lens to have a funnel-shaped configuration, i.e. without any constriction.
2. Spectacle lens according to claim 1 ,
wherein only one surface contributes to the increase of the power in a wearing position.
3. Spectacle lens according to claim 2 ,
wherein this surface is an eye-side surfaces.
4. Spectacle lens according to claim 3 ,
wherein the other surface is a rotationally symmetrical or toroidal surface.
5. Spectacle lens according to claim 4 ,
wherein for a non-astigmatic eye the region of clear vision is bounded by a 0.5 dpt isometric line of surface astigmatism.
6. Spectacle lens according to claim 5 ,
wherein a course of a first derivative of the power along the principal line is monotonous between the first and the second see-through regions.
7. Spectacle lens according to claim 6 ,
wherein the course of the first derivative of the power along the principal line is monotonous between the second see-through region and the lower edge of the spectacle lens.
8. Spectacle lens according to claim 7 ,
wherein the spectacle lens has a same diameter as a conventional spectacle lens with progressive power, i.e. a spectacle lens with a region designed for distant viewing and a region designed for near viewing.
9. Spectacle lens according claim 8 ,
wherein a surface or surfaces which contribute to an increase of power in the wearing position have been individually computed for a respective wearing situation.
10. Spectacle lens according to claim 9 ,
wherein isometric lines of a power increase extend horizontally in a region of a principal visual axis.
11. Spectacle lens according to claim 10 ,
wherein at least the isometric lines of power increase passing through the principal line above a center between points B F and “B N ” are curved upwards laterally of the principal line and meet the edge of the spectacle lens at a value of a y coordinate which is higher than a value of a y coordinate at which they pass through the principal line.
12. Spectacle lens according to claim 11 ,
wherein a distance reference point (B F ) and a centration point (Z P ) coincide.
13. Spectacle lens according to claim 1 ,
wherein the other surface is a rotationally symmetrical or toroidal surface.
14. Spectacle lens according to claim 1 ,
wherein for a non-astigmatic eye the region of clear vision is bounded by a 0.5 dpt isometric line of surface astigmatism.
15. Spectacle lens according to claim 1 ,
wherein the spectacle lens has a same diameter as a conventional spectacle lens with progressive power, i.e. a spectacle lens with a region designed for distant viewing and a region designed for near viewing.
16. Spectacle lens according claim 1 ,
wherein a surface or surfaces which contribute to an increase of power in the wearing position have been individually computed for a respective wearing situation.
17. Spectacle lens according to claim 1 ,
wherein isometric lines of a power increase extend horizontally in a region of a principal visual axis.
18. Spectacle lens according to claim 1 ,
wherein a distance reference point (B F ) and a centration point (Z P ) coincide.
19. A spectacle lens comprising:
a lower edge;
a first see-through region having a power suitable for viewing at a far distance in a wearing position;
a second see-through region having a power suitable for viewing at a medium distance of about one meter and more in a wearing position;
a plane or winding principal line, wherein power continually increases from the first see-through region along the plane or winding principal line to the second see-through region and beyond the second see-through region to the lower edge; and
a region of clear vision in which a residual astigmatism of a system spectacle-lens/eye does not exceed 0.5 dpt, wherein the region of clear vision narrows below the first see-through region towards the lower edge to have a funnel-shaped configuration without any constriction.
20. The spectacle lens according to claim 1 , further comprising first and second surfaces, wherein only one of the first and second surfaces contributes to the increase of the power.
21. The spectacle lens according to claim 20 ,
wherein the one of the first and second surfaces is an eye-side surface.
22. The spectacle lens according to claim 21 ,
wherein the other surface is a rotationally symmetrical or toroidal surface.
23. The spectacle lens according to claim 20 ,
wherein the other surface is a rotationally symmetrical or toroidal surface.
24. The spectacle lens according to claim 23 ,
wherein for a non-astigmatic eye the region of clear vision is bounded by a 0.5 dpt isometric line of surface astigmatism.
25. The spectacle lens according to claim 24 ,
wherein a first derivative of the power along the principal line is monotonous between the first and the second see-through regions.
26. The spectacle lens according to claim 25 ,
wherein the first derivative of the power along the principal line is monotonous between the second see-through region and the lower edge of the spectacle lens.
27. The spectacle lens according to claim 24 ,
wherein a first derivative of the power along the principal line is monotonous between the second see-through region and the lower edge of the spectacle lens.
28. The spectacle lens according to claim 27 , further having a diameter, wherein the diameter of the spectacle lens is the same as that of a spectacle lens with a region designed for distant viewing and a region designed for near viewing.
29. The spectacle lens according to claim 28 ,
wherein the surface which contributes to the increase of the power is individually computed for a specific wearing situation.
30. The spectacle lens according to claim 29 , further comprising principal visual axis, wherein isometric lines of power increase extend horizontally in a region of the principal visual axis.
31. The spectacle lens according to claim 30 ,
wherein at least the isometric lines of power increase passing through the principal line above a center between points B F and B N are curved upwards laterally of the principal line and meet the edge of the spectacle lens at a value of a y coordinate which is higher than a value of a y coordinate at which they pass through the principal line.
32. The spectacle lens according to claim 31 , further comprising a distance reference point (B F ) and a centration point (Z P ), wherein the distance reference point (B F ) and centration point (Z P ) coincide.