Abstract: A blocking system for supporting a lens blank having a first cut, posterior surface for a contact lens or an intraocular lens and a reference surface includes a block having a forward extension with a cylindrical side wall and front surface complementary to the posterior surface of the lens blank. A disposable, annular collar of synthetic resin surrounds the cylindrical extension. The top edge of the collar abuts the reference surface of the lens blank and serves to determine the location of the posterior surface during cutting the front surface of the lens. The shaped and/or the cylindrical extension may be separable from the blocking member such as a plastic cap having a shank frictionally received in a cavity in the front surface of the blocking member or a plastic cap adhered to the end of the cylindrical extension.

Abstract: A base lens blocking system comprises a blocking member formed of a flange with a rearward directed shank received in a collet of a spindle, preferably, a dead length, recessed collet. The front surface of the flange contains a lens blank engaging region which can be recessed. The lens blank is applied to the flat, front surface of the flange by means of a disc of adhesive tape, either a thermoplastic adhesive or a double-sided pressure sensitive adhesive tape or a very thin film of wax applied to a heated surface of the flange under a pressure from 5-20 pounds. A batch of blocked lens blanks can be cut with base curves and processed to finished lenses without measuring the center thickness of the base curves of each lens.

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.