Bi-aspherical type progressive-power lens and method of designing the same

A method of designing 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 far vision diopter measurement position F1, 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 near vision diopter measurement position N1, are DHn and DVn respectively, the relation of DHn and DVn is expressed by
• DHf+DHn<DVf+DVn, and DHn<DVn,
• surface astigmatism components at F1 and N1 of the first refractive surface are offset by the second refractive surface, and a combination of the first and second refractive surfaces gives a far vision 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 far vision diopter measurement position F1, a distribution of astigmatism on the second refractive surface is bilaterally asymmetrical with respect to one meridian passing through a far vision diopter measurement position F2 of the second refractive surface, and a position of a near vision diopter measurement position N2 on the second refractive surface is shifted inward to a nose by a predetermined distance.

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,

• 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 far vision diopter measurement position F1, 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 near vision diopter measurement position N1, are DHn and DVn respectively, the relation of DHn and DVn is expressed by
• DHf+DHn<DVf+DVn, and DHn<DVn,
• surface astigmatism components at F1 and N1 of the first refractive surface are offset by the second refractive surface, and a combination of the first and second refractive surfaces gives a far vision diopter (Df) and an addition diopter (ADD) based on prescription values, and
• a distribution of average diopter on the first refractive surface is bilaterally symmetrical with respect to one meridian passing through the far vision diopter measurement position F1, a distribution of average diopter on the second refractive surface is bilaterally asymmetrical with respect to one meridian passing through a far vision diopter measurement position F2 of the second refractive surface, and a position of a near vision diopter measurement position N2 on the second refractive surface is shifted inward to a nose by a predetermined distance.

A method of designing 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 far vision diopter measurement position F1, 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 near vision diopter measurement position N1, are DHn and DVn respectively, the relation of DHn and DVn is expressed by
• DHf+DHn<DVf+DVn, and DHn<DVn,
• surface astigmatism components at F1 and N1 of the first refractive surface are offset by the second refractive surface, and a combination of the first and second refractive surfaces gives a far vision diopter (Df) and an addition diopter (ADD) based on prescription values, and
• a distribution of average diopter on the first refractive surface is bilaterally symmetrical with respect to one meridian passing through the far vision diopter measurement position F1, a distribution of average diopter on the second refractive surface is bilaterally asymmetrical with respect to one meridian passing through a far vision diopter measurement position F2 of the second refractive surface, and a position of a near vision diopter measurement position N2 on the second refractive surface is shifted inward to a nose by a predetermined distance.

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 far vision diopter measurement position F1, 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 near vision diopter measurement position N1, are DHn and DVn respectively, the relation of DHn and DVn is expressed by
• DVn−DVf>ADD/2,
• surface astigmatism components at F1 and N1 of the first refractive surface are offset by the second refractive surface, and a combination of the first and second refractive surfaces gives an addition diopter (ADD) based on prescription values, and
• on a sectional curve in the vertical direction passing through F1, at an arbitrary position in a rectangle surrounded by two horizontal lines located at ±4 mm in the vertical direction, with a position providing 50% of a change of a sectional diopter in the vertical direction ranging from F1 to the same height as N1 being the center, and two vertical lines located at ±15 mm in the horizontal direction from a straight line in the vertical direction passing through F1,
• a surface sectional diopter in the vertical direction on the first refractive surface has differential values such that the absolute value of a differential value in the vertical direction is larger than the absolute value of a differential value in the horizontal direction.

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 far vision diopter measurement position F1, 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 near vision diopter measurement position N1, are DHn and DVn respectively, the relation of DHn and DVn is expressed by
• DVn−DVf>ADD/2,
• surface astigmatism components at F1 and N1 of the first refractive surface are offset by the second refractive surface, and a combination of the first and second refractive surfaces gives an addition diopter (ADD) based on prescription values, and
• on a sectional curve in the vertical direction passing through F1, at an arbitrary position in a rectangle surrounded by two horizontal lines located at ±4 mm in the vertical direction, with a position providing 50% of a change of a sectional diopter in the vertical direction ranging from F1 to the same height as N1 being the center, and two vertical lines located at ±15 mm in the horizontal direction from a straight line in the vertical direction passing through F1,
• a surface astigmatism amount on the first refractive surface has differential values such that the absolute value of a differential value in the vertical direction is larger than the absolute value of a differential value in the horizontal direction, and
• at an arbitrary position in the rectangle,
• a surface average diopter on the first refractive surface has differential values such that the absolute value of a differential value in the vertical direction is larger than the absolute value of a differential value in the horizontal direction.

A method of designing 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 far vision diopter measurement position F1, 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 near vision diopter measurement position N1, are DHn and DVn respectively, the relation of DHn and DVn is expressed by
• DVn−DVf>ADD/2,
• surface astigmatism components at F1 and N1 of the first refractive surface are offset by the second refractive surface, and a combination of the first and second refractive surfaces gives an addition diopter (ADD) based on prescription values, and
• on a sectional curve in the vertical direction passing through F1, at an arbitrary position in a rectangle surrounded by two horizontal lines located at ±4 mm in the vertical direction, with a position providing 50% of a change of a sectional diopter in the vertical direction ranging from F1 to the same height as N1 being the center, and two vertical lines located at ±15 mm in the horizontal direction from a straight line in the vertical direction passing through F1,
• a surface sectional diopter in the vertical direction on the first refractive surface has differential values such that the absolute value of a differential value in the vertical direction is larger than the absolute value of a differential value in the horizontal direction

A method of designing 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 far vision diopter measurement position F1, 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 near vision diopter measurement position N1, are DHn and DVn respectively, the relation of DHn and DVn is expressed by
• DVn−DVf>ADD/2,
• surface astigmatism components at F1 and N1 of the first refractive surface are offset by the second refractive surface, and a combination of the first and second refractive surfaces gives an addition diopter (ADD) based on prescription values, and
• on a sectional curve in the vertical direction passing through F1, at an arbitrary position in a rectangle surrounded by two horizontal lines located at ±4 mm in the vertical direction, with a position providing 50% of a change of a sectional diopter in the vertical direction ranging from F1 to the same height as N1 being the center, and two vertical lines located at ±15 mm in the horizontal direction from a straight line in the vertical direction passing through F1, a surface astigmatism amount on the first refractive surface has differential values such that the absolute value of a differential value in the vertical direction is larger than the absolute value of a differential value in the horizontal direction, and
• at an arbitrary position in the rectangle,
• a surface average diopter on the first refractive surface has differential values such that the absolute value of a differential value in the vertical direction is larger than the absolute value of a differential value in the horizontal direction.