Contact lenses are small lenses made from various polymers which are designed to be inserted into the eye over the cornea for the purpose of correcting vision; it is also possible to find contacts which just change eye color or novelty contacts for costumes. There are a number of different types of contact lenses on the market, from classic “hard” polymethyl methacrylate (PMMA) lenses to daily disposables. An optometrist can provide more advice about the types which may be right for you, depending on your unique needs and the health of your eyes, but it can help to have a general idea of your options before meeting with an optometrist to discuss contacts.
PMMA lenses were among the first contacts to be released on the market. They are not very comfortable, although they are durable and they have a long life; most people who want longer-lasting contacts prefer to use rigid gas permeable lenses. These lenses strike a balance between soft contacts and true hard contacts, lasting several years with appropriate use. Rigid gas permeables also come with less risk of corneal irritation, since they allow plenty of oxygen to reach the eye, and they tend to yield a crisper correction.
In the world of soft contacts, there are a lot of options. Soft contacts are made from more flexible polymers, making them more comfortable to wear. There are a number of styles of soft contacts available; daily disposables are designed to be worn once and thrown away, disposables are designed to be used for three to six months, and regular soft contacts can last around a year with proper care. It is also possible to purchase extended wear soft contacts, which can be left in for a week to a month; this is not safe with regular varieties of soft contacts, because extended wear contacts are specially designed for this purpose, allowing more oxygen to the eye than regular contacts to reduce the risk of irritation and infection.
There are also a number of specialty contacts available. It is possible to purchase bifocal contact lenses, colored contact lenses with corrective prescriptions, UV-blocking contacts, and contacts to treat astigmatism. Some optometrists also offer orthokeratology, commonly called ortho-k, lenses. Ortho-k lenses actually reshape the cornea while the wearer sleeps, allowing people to go without corrective eyewear during the day. These lenses are only effective when worn regularly, as the cornea will spring back if these special corrective lenses are left out for several days. For costumes, people can purchase colored contacts or contacts which change the color of the whole eye or the shape of the pupil; these contacts should always be purchased from a licenses optometrist to ensure that they are the right fit.
No matter what kind of contact lenses you decide to use, make sure to take good care of them. Always clean your contacts with a contact lens solution after taking them out for the night, and make sure that your lenses are kept in a clean container when they are not in your eyes. If you experience sore eyes, redness, swelling, or other uncomfortable symptoms, take out your contacts and make an appointment with your optometrist.