| 摘要 |
A progressive power lens with less image sway is provided. A method of designing a progressive power lens includes preferentially selecting a spectacle specification including a first condition if an average prescription power of a distance portion is equal to or greater than +3.0 D, and preferentially selecting a spectacle specification including a second condition if the average prescription power is equal to or smaller than -3.0 D. In a progressive power lens, at least a surface power OHPf in a horizontal direction of a distance portion on an object-side surface is greater than a surface power OVPf in a vertical direction, or a surface power OHPn in a horizontal direction of a near portion is greater than a surface power OVPn in a vertical direction. An eyeball-side surface includes elements that cancel shifts in the surface power by elements of a toric surface on the object-side surface. The first condition includes a condition that the surface power OVPf is greater than the surface power OVPn, and the second condition includes a condition that the surface power OVPf is smaller than the surface power OVPn. |
