PROGRESSIVE ADDITION LENS AND METHOD FOR DESIGNING PROGRESSIVE ADDITION LENS

• US 20150055083A1
• Filed: 04/05/2013
• Published: 02/26/2015
• Est. Priority Date: 04/05/2012
• Status: Abandoned Application

• Current Assignee: EHS Lens Philippines, Inc.
• Original Assignee: Hoya Lens Manufacturing Philippines, Inc. (Hoya Corporation)
• Inventors: Mori, Takateru, Shinohara, Toshihide, Kaga, Tadashi
• Application Number:
  US14/390,942
• Publication Number:
  US 20150055083A1
• Time in Patent Office: Days
• US Class Current: 351/159.42
• CPC Class Codes: G02C 7/024 Methods of designing ophthalmic lenses
• CPC Class Codes: G02C 7/063 Shape of the progressive surface
• CPC Class Codes: G02C 7/068 Special properties achieved by the combination of the front and back surfaces

Abstract

There is provided a progressive addition lens, including: a distance portion and a near portion; an object side surface including a first toric surface element; and an eyeball side surface including a second toric surface element that cancels the first toric surface element, wherein the first toric surface element is the element in which a vertical surface power OVPf₁ at a distance reference point which is previously defined in the distance portion on the object side surface, is larger than a horizontal surface power OHPf₁ at the distance reference point, and OVPf₁ is not less than a vertical surface power OVPn₁ at a near reference point which is previously defined in the near potion on the object side surface.

Claims

1. A progressive addition lens, comprising:

a distance portion and a near portion;

an object side surface including a first toric surface element; and

an eyeball side surface including a second toric surface element that cancels the first toric surface element,

wherein the first toric surface element is the element in which a vertical surface power OVPf₁ at a distance reference point which is previously defined in the distance portion on the object side surface, is larger than a horizontal surface power OHPf₁ at the distance reference point, and OVPf₁ is larger than a vertical surface power OVPn₁ at a near reference point which is previously defined in the near potion on the object side surface.

2. The progressive addition lens according to claim 1, wherein the first toric surface element is the element in which OVPn₁ is larger than horizontal surface power OHPn₁ at the near reference point.

3. The progressive addition lens according to claim 2, wherein regarding the second toric surface element, vertical surface power IVPf1 at a point corresponding to the distance reference point on the eyeball-side surface, horizontal surface power IHPf1 at a point corresponding to the distance reference point, vertical surface power IVPn₁ at a point corresponding to the near reference point on the eyeball-side surface, and horizontal surface power IHPn₁ corresponding to the near reference point, and OVPf₁, OHPf₁, OVPn₁, and OHPn₁, satisfy the following conditions.

IVPf₁−

IHPf₁=OVPf₁−

OHPf₁

IVPn₁−

IHPn₁=OVPn₁−

OHPn₁

wherein astigmatic prescription is not included, and IVPf₁, IHPf₁, IVPn₁, and IHPn₁ are absolute values.

4. The progressive addition lens according to claim 1, wherein the object-side surface includes a toric surface, in which a vertical surface power is larger than a horizontal surface power, and a difference between the vertical surface power and the horizontal surface power is constant.

6. The progressive addition lens according to claim 2, wherein the object-side surface includes a toric surface, in which a vertical surface power is larger than a horizontal surface power, and a difference between the vertical surface power and the horizontal surface power is constant.

7. The progressive addition lens according to claim 3, wherein the object-side surface includes a toric surface, in which a vertical surface power is larger than a horizontal surface power, and a difference between the vertical surface power and the horizontal surface power is constant.

5. A method for designing a progressive addition lens comprising a distance portion and a near portion, the method comprising:

designing an object-side surface so as to include a first toric surface element and

designing an eyeball-side surface so as to include a second toric surface element that cancels the first toric surface element,

wherein the first toric surface element is the element in which a vertical surface power OVPf₁ at a distance reference point which is previously defined in the distance portion on the object side surface, is larger than a horizontal surface power OHPf₁ at the distance reference point, and OVPf₁ is larger than a vertical surface power OVPn₁ at a near reference point which is previously defined in the near potion on the object side surface.