Patent ID: 11960149
Assignee: HOYA LENS THAILAND LTD.
Field: Optics (Instruments)
Classification: CPC G  A | IPC G

Claim 7:
8. A method for designing a progressive power lens, comprising:
a step (a) of ascertaining a head rotation amount that is generated by a subject in a sagittal plane of the subject when gazing at each of a plurality of gaze points that are set at predetermined and known distances different from each other in a forward depth direction with respect to the subject;
a step (b) of determining an eyeball rotation amount that is generated by the subject when gazing at each of the plurality of gaze points, based on an assumption that a line-of-sight angle from the subject's eyes to the plurality of gaze points when the subject is gazing at each of the plurality of gaze points is equal to a sum of the head rotation amount and the eyeball rotation amount, the number of gaze points being at least three;
a step (c) of judging visual behavior of the subject by using the head rotation amount and the eyeball rotation amount, or using the eyeball rotation amount;
a step (d) of determining a correction method for correcting a progressive power lens based on a result of judgement made in the step (c); and
a step (e) of correcting a design of the progressive power lens based on the correction method determined in the step (d).