A display device comprises a waveguide configured to guide light in a lateral direction parallel to an output surface of the waveguide. The waveguide is further configured to outcouple the guided light through the output surface. The display device additionally comprises a broadband adaptive lens assembly configured to incouple and to diffract therethrough the outcoupled light from the waveguide. The broadband adaptive lens assembly comprises a first waveplate lens comprising a liquid crystal (LC) layer arranged such that the waveplate lens has birefringence (Δn) that varies in a radially outward direction from a central region of the first waveplate lens and configured to diffract the outcoupled light at a diffraction efficiency greater than 90% within a wavelength range including at least 450 nm to 630 nm. The broadband adaptive lens assembly is configured to be selectively switched between a plurality of states having different optical powers.