Patent ID: 7731357

Claim:
A method for producing a group of bi-aspherical type progressive-power lenses with each lens having a progressive refractive power action dividedly allotted to a first refractive surface being an object side surface and a second refractive surface being an eyeball side surface, in which lens, when a surface refractive power in a horizontal direction and a surface refractive power in a vertical direction, at a far vision power measurement position F 1 on the first refractive surface are DHf and DVf respectively, and a surface refractive power in a horizontal direction and a surface refractive power in a vertical direction, at a near vision power measurement position N 1 on the first refractive surface are DHn and DVn respectively, a relational expression expressed by the following expressions is satisfied, DHf+DHn<DVf+DVn, and DHn<DVn, surface astigmatism components at F 1 and N 1 on the first refractive surface are cancelled by the second refractive surface, and a combination of the first and second refractive surfaces gives a far vision power (Df) and an addition power (ADD) based on a prescription value, said method comprising: producing the group of bi-aspherical type progressive-power lenses so that the same first refractive surface is used for at least two or more lenses of different addition powers.