LINSE

A convex lens has a geometric axis, defined to be an axis passing through the lens at a central point normally to the general plane of the lens, spaced from its optical axis defined to be an axis passing through the lens between its focal points. The lens may be manufactured from a mould, at least one concave surface of which has a centre point spaced from a deepest point, said mould having a feed point at an edge point substantially in a plane extending from said centre point through said deepest point to the edge of the concave surface. A transparent plastics material may then be injected into the mould cavity through the feed point.