METHOD FOR MINIMIZING MAXIMUM THICKNESS OF LENS FOR MONOFOCAL SPECTACLES AND LENS FOR MONOFOCAL SPECTACLES WITH GRADIENT IN REFRACTIVE INDEX MANUFACTURED THEREBY

摘要

PURPOSE: To optionally minimize maximum thickness by defining a system for changing a refractive index by a rule that the absolute value of optical magnification of a lens is sharply larger than geometric magnification at the time of calculating the optical magnification by using a refractive index on the optical axis of the lens. CONSTITUTION: The maximum thickness of a single focus glasses lens having a partially spherical convex face 10 on one side and a concave face 11 and capable of changing its refractive index in the diameter direction from the optical axis X of the lens to its periphery is minimized. The system for changing the refractive index is defined by the rule that the absolute value of optical magnification of the lens is sharply larger than geometric magnification at the time of calculating the optical magnification by using the refractive index on the optical axis X of the lens. The absolute value of the optical magnification is at least 1.5 times the geometric magnification. Consequently, the single focus glass lens allowed to be easily worked and capable of sufficiently correcting astigmatism and field curvature aberration and suitably reducing the maximum thickness is manufactured.