How Are Contact Lenses Made?
By Steve Ecclestone Exactly how are contact lenses made? Many people wear them but few know how a contact lens is made. Contact lenses can come in a variety of shapes, sizes and color . The most popularly used contact eye lenses today are the soft variety. The first soft contact lenses were developed in 1960 – but it was only in 1971 when the public had access to eye contacts. Toric eye lenses for astigmatism were approved for use in 1978. The first rigid gas permeable lenses were introduced in 1979. Subsequent advances in eye wear technology saw the introduction of bifocal eye lenses, tinted eye lenses, daily wear soft lenses, and disposable contacts. In the nineties, eye wear became even more advanced when companies started introducing disposable tinted eye lenses, and disposable contacts with UV protection. How Are Contact Lenses Made Exactly? In most cases, the manufacturing of lenses is automated. Key factors companies use to determine the type of lens include 1) Total power the f
When making soft contact lenses, manufacturers start with a polymer that has been cut into buttons. Guided by a computer, a digital lathe shapes the inside of the contact based on the lens prescription. The inside of the lens is then polished with an abrasive paste to remove any imperfections that could interfere with vision or comfort. Lens thickness is measured and, if correct, the lens is coated in wax so that the outside of the lens can be molded to the desired shape. Once the outside of the lens has been shaped, ultrasound is used to remove the wax and the outer surface and rims of the lens are polished. The lens is then left in a saline solution for 24 hours so that it can absorb enough liquid to become soft and flexible. The lens is then checked to verify that it matches the prescription and correctly refracts light. After a final cleaning, the lenses are sealed in bottles of a salt solution. These containers are then sterilized and can remain so for up to 7 years. Lenses can al
