Method for designing eyeglass lens and method for manufacturing the same
A method for designing an eyeglass lens includes: a basic value calculation step of determining a basic visualizing action index representing a visualizing action taken when a person who wears no eyeglasses or single-vision lenses looks at an object; a progressive value calculation step of determining a progressive visualizing action index representing a visualizing action taken when the person who wears reference progressive addition lenses looks at the object; and a lens designing step of enlarging the field of view as compared with that of the reference progressive addition lenses when the progressive visualizing action index shows greater head movement than the basic visualizing action index does, whereas enlarging an aberration region as compared with that of the reference progressive addition lenses when the progressive visualizing action index shows smaller head movement than the basic visualizing action index does.
1. A method for designing an eyeglass lens, the method comprising:
determining a basic visualizing action index representing a visualizing action taken when a person who wears no eyeglasses or single-vision lenses looks at an object;
determining a progressive visualizing action index representing a visualizing action taken when the person who wears reference progressive addition lenses looks at the object; and
enlarging the field of view as compared with that of the reference progressive addition lenses when the progressive visualizing action index shows greater head movement than the basic visualizing action index does, whereas enlarging an aberration region as compared with that of the reference progressive addition lenses when the progressive visualizing action index shows smaller head movement than the basic visualizing action index does.
2. The method for designing an eyeglass lens according to claim 1 ,
wherein the determining a basic visualizing action index includes measuring an angle βs n between the direction facing the person and the direction in which the head is oriented when the person looks at an object located in the direction inclined to the direction facing the person by an angle α n and calculating a basic visualizing action index Ms n by using the following Equation (1):
Ms
n
=
β
s
n
α
n
(
n
=
1
,
2
)
(
1
)
(in Equation (1), n represents each object)
the determining a progressive visualizing action index includes measuring an angle βp n between the direction facing the person and the direction in which the head is oriented when the person looks at the object located in the direction inclined to the direction facing the person by the angle α n and calculating a progressive visualizing action index Mp n by using the following Equation (2):
Mp
n
=
β
p
n
α
n
(
n
=
1
,
2
)
(
2
)
(in Equation (2), n represents each object)
and the enlarging the field of view includes selecting a design type determined in advance for the basic visualizing action index and the progressive visualizing action index.
3. A method for manufacturing an eyeglass lens based on the method for designing an eyeglass lens according to claim 1 .