Patent ID: 7399080

Claim:
a bi-aspherical type progressive-power lens with 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, wherein when on the first refractive surface, a surface refractive power in a horizontal direction and a surface refractive power in a vertical direction, at a farsightedness diopter measurement position F 1 , are DHf and DVf respectively, and on the first refractive surface, a surface refractive power in a horizontal direction and a surface refractive power in a vertical direction, at a nearsightedness diopter measurement position N 1 , are DHn and DVn respectively, relation of DHn and DVn are expressed by DHf+DHn<DVf+DVn , and DHn<DVn, surface astigmatism components at F 1 and N 1 of the first refractive surface are offset by the second refractive surface, and a combination of the first and second refractive surfaces gives a farsightedness diopter (Df) and an addition diopter (ADD) based on prescription values, and a distribution of astigmatism on the first refractive surface is bilaterally symmetrical with respect to one meridian passing through the farsightedness diopter measurement position F 1 , a distribution of astigmatism on the second refractive surface is bilaterally asymmetrical with respect to one meridian passing through a farsightedness diopter measurement position F 2 of the second refractive surface, and a position of a nearsightedness diopter measurement position N 2 on the second refractive surface is shifted inward to a nose by a predetermined distance.