A method and apparatus for facilitating controllable switching an interface (12) between a reflective state in which light (14) incident upon the interface undergoes total internal reflection, and a non-reflective state in which total internal reflection is prevented at the interface. The apparatus incorporates a member (10 - preferably an elastomer) which is deformable with respect to the interface. The member's Young's Modulus in portions (18) of the member adjacent the interface is substantially greater (i.e. stiffer) than the member's Young's Modulus in portions of the member away from the interface. The stiffened portion of the member adjacent the interface may be in the form of a microstructure (20). A pair of electrodes (22, 24) coupled to a voltage source can be provided to controllably deform the member into optical contact with the interface, within a continuously variable range of optical contact values, to produce the non-reflective state in selectably varying degrees.