A liquid progressive multifocal lens adjusted by the deformation of a non-uniform elastic membrane due to the variation of liquid pressure.

Background: In this paper, a liquid progressive multifocal lens with solid-liquid structure is demonstrated, which mainly consists of two elastic polydimethylsiloxane (PDMS) membranes, a solid substrate and liquid. Methods: To realize the adjustment of the focuses progressively, the thickness of one of the membrane is designed non-uniform. By controlling the liquid pressure working on the membranes, the curvature of the membrane can be changed continuously and the power of the lens can be altered simultaneously. In this paper, the structure and a fabrication method of the lens is introduced, and a power distribution model is built for the calculation of the power distribution characteristics. Moreover, the deformation of the non-uniform elastic membrane of the lens under different pressures is analysed with finite element method (FEM). Results: Finally, a prototype of the lens is developed and tested by applying a micro laser displacement sensor, and it is demonstrated that the progressive multifocal lens is feasible. Conclusion: A novel liquid progressive multifocal lens with a non-uniform thickness elastic membrane is proposed. From the simulation and experimental investigation, it can be concluded that the proposed liquid lens can realize progressive multifocal through using non-uniform elastic membrane and the power can be adjusted by the pressure which is controlled by the liquid volume filled in the lens. [ABSTRACT FROM AUTHOR]