Design of high-power aspherical ophthalmic lenses with a reduced error budget

As in the lens optimization process, ophthalmic lens designers have usually constructed error functions with 0.5, 0.7, and 1.0 at only three oblique fields. This seems enough to achieve a balanced trade-off with the astigmatic error, the power error, and the distortion all being considered simultaneously. However, for high-power ophthalmic lenses, the aberration curves show serious violations even if aspherical coefficients are involved. The analytical results indicate that a field error suppression of up to 7 points may even be required in some cases. The suppression effects are excellent and examples of both positive and negative lenses are designed.