Provided are a liquid crystal lens, an optical filter, and a display device. The exemplary liquid crystal lens may exhibit optical anisotropy and optical isotropy according to a polarization state of incident light. When the liquid crystal lens is applied to a display device capable of generating a 2D image and a 3D image, the 3D image may be seen without glasses in the state of the optical anisotropy, and the 2D image can be seen in the state of the optical isotropy.