Optical Imaging Lens systems and components

A variable optical system comprises a variable optical assembly including a plurality of deformable layers, selectively operable to vary at least one of: an optical property of at least one of the layers, a physical property of at least one of the layers, and an optical performance of the assembly, while maintaining a constant mass in each layer, wherein each layer has an optical function. A constant volume may be maintained in each layer depending on the material used in each layer. Arrangements employing various combinations of materials forming the optical assembly and other optical systems and components are disclosed.