Novel switching mode in a vertically aligned liquid crystal contact lens

Liquid crystal (LC) contact lenses are emerging as an exciting technology for vision correction. A homeotropically (vertical) aligned LC lens is reported that offers improved optical quality and simplified construction techniques over previously reported LC contact lens designs. The lens has no polarization dependence in the off state and produces a continuous change in optical power of up to 2.00 ± 0.25 D with a voltage applied. The variation in optical power results from the voltage-induced change in refractive index of the nematic LC layer, from 1.52 to a maximum of 1.72. One device substrate is treated with an alignment layer that is a mixture of planar and homeotropic polyimides, rubbed to induce a preferred director orientation in the switched state. Defects that could occur during switching are thus avoided and the lens exhibits excellent optical quality with a continuous variation in focal power.