Contact Lens

Patent metadata

Field	Value
Publication number	US-10175504-B2
Application number	US-201515510928-A
Country	US
Kind code	B2
Filing date	Oct 1, 2015
Priority date	Oct 1, 2015
Publication date	Jan 8, 2019
Grant date	Jan 8, 2019

Abstract

To provide a contact lens with novel structure that is able to achieve both stability of the lens circumferential position in the worn state and improved wearing comfort at a high level. A first thick part and a second thick part are provided on a peripheral zone at both left and right sides such that each center-of-gravity position of both the first thick part and the second thick part is positioned below a horizontal diametrical line. A third thick part is provided on the peripheral zone below an optical zone. An upper thin part and a lower thin part are provided respectively at an upper peripheral zone positioned above the optical zone and a lower peripheral zone positioned below the optical zone and at an outer circumference side of the third thick part.

First claim

The invention claimed is:

1. A contact lens comprising: an optical zone; and a peripheral zone surrounding the optical zone, wherein
a first thick part and a second thick part are provided on the peripheral zone at sections positioned at both left and right sides in a worn state of the contact lens such that each center-of-gravity position of both the first thick part and the second thick part is positioned below a horizontal diametrical line in the worn state,
a third thick part is provided on the peripheral zone at a section positioned between the first thick part and the second thick part in a circumferential direction and entirely below the optical zone in the worn state, and
an upper thin part and a lower thin part whose thickness dimensions are smaller than thickness dimensions of the first to third thick parts are provided respectively at an upper peripheral zone positioned above the optical zone and a lower peripheral zone positioned below the optical zone and at an outer circumference side of the third thick part in the worn state.

2. The contact lens according to claim 1 , wherein a maximum thickness dimension of the third thick part is smaller than maximum thickness dimensions of the first and second thick parts.

3. The contact lens according to claim 1 , wherein a maximum thickness dimension of the third thick part is within a range of 0.2 to 0.3 mm.

4. The contact lens according to claim 1 , wherein in a vertical direction in the worn state, a maximum thickness position of the third thick part is set higher than a lower edge position of the same thickness as a maximum thickness of the third thick part with the first and second thick parts.

5. The contact lens according to claim 1 , wherein in a lens radial direction, a maximum thickness position of the third thick part is set further on an inner circumference side than an outer peripheral edge position of the same thickness as a maximum thickness of the third thick part with the first and second thick parts.

6. The contact lens according to claim 1 , wherein a minimum thickness dimension of the upper thin part is smaller than a minimum thickness dimension of the lower thin part.

7. The contact lens according to claim 1 , wherein with the upper peripheral zone for which the upper thin part is provided that is positioned above the optical zone in the worn state, a maximum thickness dimension within a scope of 5.0 degrees each to left and right around a lens center axis from a vertical diametrical line in the worn state is 0.2 mm or less.

8. The contact lens according to claim 1 , wherein each maximum thickness dimension of the first and second thick parts is 0.34 mm or less.

9. The contact lens according to claim 1 , wherein each maximum thickness dimension of the first and second thick parts is set to be +0.2 mm or less in relation to an average thickness dimension of the circumferential direction at an outer peripheral edge part of the optical zone.

10. The contact lens according to claim 1 , wherein transition parts whose thickness dimensions become gradually smaller are provided at both circumference side parts of the first and second thick parts, and a thickness change rate at a first one of the transition parts positioned lower in the circumferential direction in the worn state is greater than a thickness change rate at a second one of the transition parts positioned higher in the circumferential direction in the worn state.

11. The contact lens according to claim 1 , wherein in a vertical direction in the worn state, a displacement amount of a center-of-gravity position of an overall lens downward from a lens geometric center is 4% or greater in relation to a lens outer diameter dimension.

12. The contact lens according to claim 1 , wherein an overall lens volume is 40 mm 3 or less.

13. The contact lens according to claim 1 , wherein a prism ballast shape is set for a lens front surface and a lens back surface.

14. The contact lens according to claim 1 , wherein the first to third thick parts and the upper and lower thin parts have a linearly symmetrical shape in relation to a vertical diametrical line in the worn state.

15. The contact lens according to claim 1 , wherein the contact lens is any of a toric lens, a bifocal lens, a multifocal lens, a color contact lens, or a myopia progression suppression lens.

16. A contact lens set including a plurality of contact lenses according to claim 1 which are assorted by different spherical lens powers set for the optical zones thereof, the contact lens set being characterized in that: a prism ballast shape is set for lens front surfaces and lens back surfaces of the contact lenses, and a prism amount is set to be greater corresponding to the spherical lens powers of the optical zones being greater at a minus side.

Assignees

• Menicon Co Ltd

Inventors

• Goto Yuji
• Kimura Yuko

Classifications

• G02C7/048 Primary

  Means for stabilising the orientation of lenses in the eye · CPC title

• G02C7/04

  Contact lenses for the eyes (disinfection or sterilisation of contact lenses A61L12/00) · CPC title