Contact Lenses


So you're having vision problems and you've decided to get the predicament fixed. You've realized that you have several options when confronting vision correction. There are glasses, but some people find them awkward or simply would prefer to have a less obvious solution. Corrective surgery is now an option for some, but many shy away from this route, either for financial reasons or procedural anxiety. So what's left? Contact lenses may be the solution.

Contact lenses are pieces of plastic or synthetic material that can be inserted into the eye over the cornea to help improve vision. Contact lenses are an alternative to wearing thick glasses, making participation in various activities much easier.

A Brief History of the Contact Lenses
  • 1508 - Leonardo da Vinici, originator of the concept for contact lenses, sketched several ideas but never produced any prototypes for testing.

  • 1887 - An actual lens that can be worn is created by a German glassblower F.E. Muller.

  • 1936-1939 – In the United States, contact lenses are designed and perfected in plastic.

  • 1971 - Commercial distribution of soft contact lenses begins in the U.S.

  • 1979 - The first Rigid Gas Permeable (RGP) lenses are designed.

  • 1987 - Disposable soft contacts become available for mass distribution.

  • 1996 - The first disposable contacts with ultraviolet absorber are available in the United States.
Steps the Getting Contact Lenses

The first step toward contact lens ownership is to visit an ophthalmologist or optometrist. Sometimes, even an optician can help meet your needs. Contact lenses are medical devices, and should only be properly fitted by the appropriate eye care specialists. In the United States, contact lense ownership can only be attained with a valid prescription.

Occasionally, there are those who cannot wear contact lenses. There are a variety of reasons for this occurrence, most notably the shape of one's eye or allergic reactions to the lenses.

Different Kinds of Contacts

Contact lens labels may look difficult to decipher, but they are actually quite simple. The abbreviations OD, OS, and OU stand for right eye, left eye, and both eyes, respectively. BC stands for the base curve and DIA stands for the diameter of the eye. The measurements for each individual's eye can vary, so all these numbers are important in making sure to meet the proper prescription.

Two types of contact lenses are most popular with consumers. The first are soft contact lenses, also called disposables. Made of a soft plastic that is cut and polished, soft contacts are made up of 25%-79% water. Because of this liquid make-up, they are the easiest to wear and the easiest to get used to.

The second are hard contact lenses. Rigid Gas Permeable lenses, RGP's, are made of silicone and allow more oxygen to be transmitted to the eye. RGP's are a better option for people who fail to adjust to soft contacts, and are also easier to clean as well. The low water content of the hard lenses takes some adjustment, but most people find them comfortable enough to wear every day once their eyes have adjusted.

All contact lenses are described in two ways: their density or hardness, and by the length of time they are to be worn. Wear schedule refers to whether you may sleep in your contacts. The contacts you can sleep in are called extended wear, and the others are daily wear. Daily wear and disposable models are the most popular to date, but new advances in optometry have made 30-day continuous wear contact lenses both affordable and available. They are expected to flood the marketplace within the upcoming years.

Another feature of many contact lenses, both soft and RGP, is ultraviolet (UV) light blocking. The benefit of UV blockers in contact lenses protects against the transmission of harmful UV radiation to the cornea and the eye."

Specialty lenses are also available, including bifocal and trifocal lenses in addition to toric lenses, which help correct astigmatism.

By Blaise Morita           


Related Links:

  • Contact Lens Care
    Discusses types of contact lenses to correct various visual needs, wearing schedules, where to buy, and how to care for them.