Soft contact lenses (both hydrogel and silicone hydrogel lenses) are available in a variety of designs, depending on their intended purpose:
Spherical Contact Lenses-: have the same lens power throughout the entire optical part of the lens to correct myopia (nearsightedness) or hyperopia (farsightedness).
Toric Soft Contact Lenses- have different powers in different meridians of the lens to correct astigmatism as well as nearsightedness or farsightedness.
Multifocal Contact Lenses-: (including bifocal contacts) contain different power zones for near and far vision to correct presbyopia as well as nearsightedness or farsightedness. Some multifocal lenses also can correct astigmatism.
Cosmetic Contact Lenses-: include color contacts designed to change or intensify your eye color. Halloween, theatrical and other special-effect contacts also are considered cosmetic lenses. A contact lens prescription is required for cosmetic contacts even if you have no refractive errors that need correction.
All of these lenses can be customized for hard-to-fit eyes. Other lens designs also are available - including lenses fabricated for use in special situations, such as correcting for keratoconus.
More contact lens features-:
Bifocal contacts for astigmatism.
These are advanced soft contacts that correct both presbyopia and astigmatism, so you can remain glasses-free after age 40 even if you have astigmatism.
Contacts for dry eyes.
Are your contacts uncomfortably dry? Certain soft contact lenses are specially made to reduce the risk of contact lens-related dry eye symptoms.
Many of the types of lenses described above also come in colors that can enhance the natural color of your eyes - that is, make your green eyes even greener, for example. Other colored lenses can totally change the color of your eyes, as in from brown to blue.
Also called theatrical, novelty, or costume lenses, special-effect contacts take coloration one step further to make you look like a cat, a vampire, or another alter-ego of your choice.
Colored contact lenses also can be used for more medically oriented purposes. Opaque soft lenses called prosthetic contacts can be custom-designed for an eye that has been disfigured by injury or disease to mask the disfigurement and match the appearance of the other, unaffected eye.
If conventional contact lenses don't seem to work for you, you might be a candidate for custom contact lenses that are made-to-order for your individual eye shape and visual needs.
Some soft contact lenses help protect your eyes from the sun's ultraviolet rays that can cause cataracts and other eye problems. But because contacts don't cover your entire eye, you still should wear UV-blocking sunglasses outdoors for the best protection from the sun.
Large-diameter gas permeable lenses called scleral contacts are specially designed to treat keratoconus and other corneal irregularities, as well as presbyopia. Myopia control contacts. Special contact lenses are being developed to slow or stop the progression of nearsightedness in children.