| 摘要 |
PROBLEM TO BE SOLVED: To provide a production method of a precursor lens for a globe lens, wherein even if the precursor lens having a large change in the thickness in a circumference direction near the rim, does not so largely change in the thickness of the rim. SOLUTION: The production method for a precursor lens 15 having a circular outer shape to be processed into a globe lens and having lens characteristics imparted thereto responding to the prescription of a user, includes inputting data for specifying a shape of the lens for spectacles in a processing data input process and processing a material block based on the processing data to prepare the precursor lens 15. When the difference between the maximum rim thickness and the minimum rim thickness of the precursor lens 15 to be prepared is equal to or larger than a predetermined difference and the astigmatic axis is AX180, the lens precursor is processed by correcting the rim thickness to be nearer to the minimum rim thickness in a region outside an elliptic region that encloses the shape of the lens for spectacles. COPYRIGHT: (C)2011,JPO&INPIT |
