A method of designing and/or selecting a progressive addition lens design for a wearer is disclosed. In an embodiment, the method includes displaying a graphical representation of an initial progressive addition lens design including design parameters having design values. A user interface is provided including, for each of one or more of the design parameters, a control that is adjustable over a range of levels, each level in the range being associated with a corresponding value of the respective design parameter. A control is adjusted to select a level and the selection is processed so as to substantially simultaneously update the displayed graphical representation in accordance with the selected level to provide a modified progressive lens design. A system for designing and/or selecting a progressive addition lens design for a wearer is also disclosed.