A switchable-focus lenticular microlens array (LMA) is an essential component for switchable 2D/3D displays. For 2D display, the LMA has no optical power and it functions as an optical flat plate. To achieve 3D display, each microlens in the array has a focusing effect. Various approaches for preparing LMAs were demonstrated. In this report, we mainly introduce two types of LMAs: polymeric LMA and polyvinyl chloride (PVC)/dibutyl phthalate (DBP) LMA. The polymeric LMA is optically anisotropic and solidified. When it integrates with a twisted-nematic liquid crystal (TN LC) polarized rotator, a switchable focus with a low driving voltage and fast response time can be obtained. As a comparison, the PVC/DBP LMA is optically isotropic and adaptive. Its focal length can be largely changed by reconfiguring its surface profile using a DC voltage. Both LMAs have the merits of compact structure, simple fabrication, and good optical performance. The operation mechanism of each LMA is introduced and their performances are evaluated. They both have potential applications in switchable 2D/3D displays.