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Free Laser Vision Screening
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Over 24 million people in the United States now wear contact lenses. Contacts provide a safe and effective way to correct vision when used properly. They can offer an excellent alternative to eyeglasses, depending on your vision and your lifestyle. What are contact lenses?Contact lenses are small, curved plastic disks designed to sit on top of the the cornea, the clear front surface of the eye. Contacts cling to the film of tears over the cornea because of water surface tension, the same force that causes a droplet of water to stick to an outside window. Contact lenses can be used to correct the same conditions that eyeglasses correct:
Special colored contacts can be used to change the color of the eyes to various degrees. Additionally, contact lenses are sometimes used in eye diseases where an irregular cornea blurs vision, such as with keratoconus or scarring. What types of contact lenses are available?PMMA lensesThese hard contacts were the first lenses; they were developed in the 1960s. They are
made of a type of plastic called PMMA, which is very durable, but does not allow oxygen in
the air to penetrate the lens and reach the cornea. Gas-permeable lensesNewer rigid lenses made of space-age plastics combined with other materials, such as silicone and fluoropolymers, allow oxygen in the air to pass directly through the lens and reach the cornea. They are called gas permeable. Gas-permeable lenses are somewhat less durable than conventional rigid lenses but are more comfortable. Some gas-permeable lenses are extended wear, and may be worn overnight for up to seven days. Soft contact lensesThese lenses are made of soft plastic materials that incorporate water. The water makes
them flexible, as well as allowing oxygen to reach the cornea. The vast majority of
contact lens wearers in the United States use soft lenses. Some soft contact lenses are
extended wear lenses, which means they are designed to be left in the eye overnight. It is
recommended that extended-wear lenses be removed weekly, at a minimum, for thorough
cleaning and disinfection. (Note: Dr. Khater does NOT reccommend that extended wear lenses
be worn overnight, because of the significant increase in risk of a blinding eye
infection.) Soft daily-wear lenses are designed to be removed at bedtime, and should never
be used as extended-wear lenses. Extended wear lenses can be used as daily-wear lenses. Toric contact lensesToric lenses are contacts that have a complex curve on one or both surfaces, and are used to correct mild to moderate astigmatism. They are available in many different materials. What does the price include?When comparing the price of contact lenses, it's important to consider what services are included. Does the fitting include a thorough eye examination and followup? Can you exchange lenses during the initial fitting, and is insurance for lost lenses available? If you need treatment for an eye condition not directly related to the contact lenses, such as inflamed eyelids or dry eyes, there may be additional charges. What are the risks of wearing contact lenses?Rigid lenses that are not gas permeable are more likely to scratch the cornea if the lens is not inserted properly or if the lens is worn while sleeping. They are also more likely to slide off the cornea and become malpositioned under the upper eyelid. Rigid lenses traditionally have had a reputation for "popping out" of the eye. Newer lens designs have minimized the chance of losing a contact even during vigorous exercise. Some lenses may allow for protein build-up, which can cause an allergic reaction and discomfort and intolerance to the lenses. You will need special cleaning solutions to remove the protein. Daily-wear lenses should never be worn as extended-wear lenses. Misuse can lead to
blinding eye infections, scarring, and blood vessel formation causing temporary and even
permanent visual loss. What is proper care of contact lenses?Contact lenses must be properly cleaned and sterilized when you remove them, to kill germs and prevent infections. At the time you insert your contact lenses, you should thoroughly rinse the case with
contact lens solution and allow it to dry. All contact lens cases need frequent cleaning,
including cases for disposable lenses. Soft extended-wear contacts are the most likely to
have protein build-up and cause lens-related problems. Soft dailywear lenses are less
likely to create these problems. Rigid gas-permeable or disposable lenses may be good
choices for someone with allergies. Additionally, any eye drops, even nonprescription ones, can interact with all types of contact lenses. Check with your ophthalmologist before you use any eye drops. Who should not wear contact lenses?Most people who need vision correction can wear contact lenses, but there are some exceptions. Some of the conditions that might keep you from wearing contact lenses are:
Are contacts for you?Whether or not contact lenses are a good choice for you depends on:
If you have any additional questions or would like further information, ask your ophthalmologist. |
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