Abstract: An eyeglass assembly comprises a lens and a frame member. One of the lens and the frame member has a recess formed in it which has a generally constant cross-section when viewed from one end along at least part of its length. The recess is defined by a pair of opposed arms with reentrant portions at their ends which define a longitudinal opening between them extending along at least part of the length of the recess, and it has an opening at one end. The other of the lens and the frame member bears a head portion. The recess and the head portion are configured so that the head portion can be fitted into the recess by sliding it through the opening at the said end of the recess, and so that the head portion is prevented by the reentrant portions of the arms from being withdrawn from the recess through the longitudinal opening.

Abstract: An eyeglass assembly which comprises a lens and a frame member, in which the lens has a lug at one edge. The assembly includes a connector by which the frame member is fastened to the lug. The connector comprises a hoop formed from a shape memory alloy which has (a) been treated so that the hoop shrinks inwardly when it is heated to a temperature at which the alloy transforms from martensite phase to austenite phase, and (b) been exposed to an increase in temperature so that the phase of the alloy changes from the martensite phase to the austenite phase and so that the connector hoop shrinks inwardly to grip the lens lug.

Abstract: An intra-luminal expander assembly for use with a catheter comprises an expandable tubular expander element having openings, for example slots, formed in it, and first and second fixation portions located at or towards its ends. The expander element is disposed around a core element which comprises a shape memory alloy which has been treated so that, when the temperature of the alloy is increased above its A.sub.s temperature, it displays a shape memory effect and the length of the core element decreases. The expander element is attached to the core element through the first fixation portion and oriented so that, as the length of the core element decreases when its temperature increases, the first fixation portion is caused to move relative to the second fixation portion in a direction towards the second fixation portion, and the second fixation portion being restrained against movement with the first fixation portion so that the length of the expander element decreases and its transverse dimension increases.