Abstract: Contact and intra-ocular lenses are manufactured by forming reference surfaces in a lens blank along with the inner base surface for the lens. The partially formed lens blank is then mounted to a blocking member which has complementary surfaces that mate with the reference surface and automatically align the lens blank. The blocking member has a flange that abuts against a spindle in which the member is held during formation of the outer lens surface. The known distance between the abutting surface of this flange and the reference surface on the lens blank allows the outer lens surface to be formed without having to separately measure the thickness of the lens blank, or enter dimensional information into the computer which controls the operation. A recessed collet within the spindle enables the blocking member flange to directly abut the end of the spindle.