An adjustable mold includes a distortable boundary, a flexible membrane, and a pressurizer, and method of use thereof. Pressure is applied to the flexible membrane, which causes the membrane to distort over the boundary. The shape of the boundary and the distortion of the flexible membrane control the optical characteristics of a lens resulting from the application and curing of a molding composition placed on the flexible membrane or to cast other items having variable shapes determined in part by the flexible membrane. In addition, a mold edge is used to allow casting in predetermined shapes, reducing need for grinding or edging. Visual and emission device calibration features used in conjunction with calibration reference images allow uniform selective distortion of the flexible membrane.