Buying online can often mean discounts of up to 60% are offered, while another advantage is easier price comparison and the fact that one can browse from home. Manufacturers of the lenses generally have their own websites, but it is recommended to do your own research prior to purchasing. Make sure you know the right brands and types of lenses that will suit your eyes. Modern, soft contact lenses were invented by Otto Witcherle and Drahoslav Lim, Czech chemists, who also invented the gel used in the first production of the lenses.
Advantages over Glasses
Contact lenses are generally more practical than glasses. They are less affected by wet weather, do not steam up and provide an unobstructed field of vision. Wearing lenses can also be used widely in sporting activities, whereas in general, wearing glasses in sport can be impractical and dangerous. In addition to this, some eye conditions may not be fully addressed through the use of glasses.
Soft or Disposable
Remember when buying lenses that you are looking for quality lenses and if you are looking for comfort, you might decide to buy soft contact lenses. Some of these lenses are tinted blue to increase visibility while out of the eye. However, if you prefer you can also choose disposable lenses, which provide a very convenient service. Many lenses are coloured in order to change the appearance of the eye and some are capable of UV protection.
Types of Lens
Diamond-turned lenses start out as a cylindrical disc, which is cut and polished on a CNC lathe. The lathe uses industrial-grade diamonds to cut the disc and after cutting, the inner concave surface of the lens is then polished with oil, abrasive paste and a small polyester cotton ball. This process is repeated on the outer side of the lens.
Some soft lenses, known as Moulded Lenses, are manufactured through the use of a rotating mould. The molten material is added to the rotating mould and shaped by centrifugal forces. Further to this, injection moulding and computer control are also used in order to gain absolute precision. Spin-cast lenses are soft lenses created by spinning liquid silicone in a high-speed revolving mould.