US Patent 7728949 Electro-active lens

Embodiments of the present invention relate to a cholesteric liquid crystalline material which may be usable in an electro-active element for providing fail safe operation, polarization insensitivity, low electrical power consumption requirements, and a small number of electrical connections. The cholesteric liquid crystalline material may be usable in an electro-active element for providing a diffractive efficiency or focusing efficiency above 90% in an activated state of the electro-active element and a diffractive efficiency or focusing efficiency below 10% in a deactivated state of the electro-active element.