US Patent 10993798 Multifocal lens having reduced chromatic aberrations

A method and system provide a multifocal ophthalmic device. The ophthalmic lens has an anterior surface, a posterior surface and at least one diffractive structure including a plurality of echelettes. The echelettes have at least one step height of at least one wavelength and not more than two wavelengths in optical path length. The diffractive structure(s) reside on at least one of the anterior surface and the posterior surface. The diffractive structure(s) provide a plurality of focal lengths for the ophthalmic lens.