Importance

Loading Importance Indicators...

Abstract

A contact lens mould for producing a contact lens. The mould comprises a first mould half having a convex moulding surface of predetermined curvature, and a second mould half having a concave moulding surface of predetermined curvature. The first mould half is provided with an annular abutment surface which circumferentially surrounds and is contiguous with the convex moulding surface, and the second mould half is provided with a flexible annular lip which circumferentially surrounds the concave moulding surface. In use, when the mould halves are brought together, the annular lip forms a continuous line contact with the abutment surface whereby a mould cavity is defined between the moulding surfaces, a radially inner surface of the annular lip and at least part of the abutment surface, and angle (.alpha.) of less than 180.degree. is defined between the abutment surface and the convex moulding surface at their intersection and an included angle (.theta.) of less than 90.degree. is defined between the abutment surface and the radially inner surface of the lip. As the mould halves are brought closer together during polymerisation, the lip flexes radially outwardly.

Loading the Abstract Image...

First Claim