Diffractive trifocal lens
    2.
    发明授权

    公开(公告)号:US11693260B2

    公开(公告)日:2023-07-04

    申请号:US17547115

    申请日:2021-12-09

    摘要: A diffractive multifocal lens is disclosed, comprising an optical element having at least one diffractive surface, the surface profile comprising a plurality of annular concentric zones. The optical thickness of the surface profile changes monotonically with radius within each zone, while a distinct step in optical thickness at the junction between adjacent zones defines a step height. The step heights for respective zones may differ from one zone to another periodically so as to tailor diffraction order efficiencies of the optical element, in one example of a trifocal lens, step heights alternate between two values, the even-numbered step heights being lower than the odd-numbered step heights. By plotting a topographical representation of the diffraction efficiencies resulting from such a surface profile, step heights may be optimized to direct a desired level of light power into the diffraction orders corresponding to near, intermediate, and distance vision, thereby optimizing the performance of the multifocal lens.

    Multifocal correction providing improved quality of vision

    公开(公告)号:US09770326B2

    公开(公告)日:2017-09-26

    申请号:US14514668

    申请日:2014-10-15

    摘要: This invention describes strategies and devices for improving the visual experience while expanding the depth of field of presbyopic and pseudophakic patients. The invention describes strategies and devices for providing improved image quality and improved visual quality of patients employing simultaneous vision bifocal, trifocal or multifocal corrections or monovision. The invention describes strategies and devices for reducing the visibility of the defocused part of the retinal image generated by simultaneous vision bifocal and multifocal ophthalmic corrections and monovision. The invention describes strategies and devices that employ control of spherical aberration or other similar asphericities to reduce the visibility of defocused ghost images. The invention describes strategies and devices that ensure that negative defocus is always coupled with negative spherical aberration (or similar asphericity), and that positive defocus is always coupled with positive SA (or similar asphericity) as a means to reduce the visibility of defocused ghost images.