Method and manufacture method of spectacle lens
A design method of a spectacle lens, includes: measuring an angle formed by a direction of a head of a person seeing the front without lens and a direction of the head of the person seeing an object located in a direction angled to the front direction of the person without lens to calculate a visual action index M n according to the following equation (1) as an initial value; temporarily designing a spectacle lens based on the visual action index; and simulating visual action of the person wearing the temporarily designed spectacle lens and correcting the visual action index based on the simulation result M n = β n α n ( 1 ) wherein α n is an angle formed by the front direction of the person and a direction in which the object actually exists, β n is a rotation angle of the head of the person seeing the object without lens, and n represents the object.
1. A design method of a spectacle lens, comprising:
measuring an angle formed by a direction of a head of a person facing a front direction without a lens and a direction of the head of the person in which an object is recognized, where the object is located in a direction angled to the front direction of the person without the lens;
calculating the angle formed by the front direction of the person and a direction in which the object actually exists to calculate a visual action index M n according to the following equation (1) as an initial value;
M
n
=
β
n
α
n
(
1
)
temporarily designing a spectacle lens based on the calculated visual action index M n ; and
simulating visual action of the person wearing the temporarily designed spectacle lens and calculating a corrected visual action index based on the simulation result
wherein α n is the angle formed by the front direction of the person and the direction in which the object actually exists,
β n is a rotation angle of the head of the person in which the object is recognized without the lens, and
n represents a number of objects; and
when n>1, then M n is calculated as an average value,
wherein the step of correcting the visual action index corrects the visual action index M n according to the following equation (2):
M′ n =M n ((α′ n +|α′ nL −α′ nR |)/α n ) (2)
wherein M′ n is a visual action index after correction,
α′ nL is an angle formed by the front direction of the person and a direction in which the object is recognized by a left eye of the person through the spectacle lens,
α′ nR is an angle formed by the front direction of the person and a direction in which the object is recognized by a right eye of the person through the spectacle lens,
α′ n is the angle corresponding to the stronger eye of the person in the angles α′ nL and α′ nR .
2. The design method of the spectacle lens according to claim 1 , wherein the step of correcting the visual action index is performed until the calculated corrected visual action index is converged.
3. A manufacture method of a spectacle lens which uses the design method of the spectacle lens according to claim 1 .