Contacts: Soft Vs. Rigid Gas-Permeable

Decisions need to be made when purchasing contact lenses. There are benefits as well as disadvantages to both soft and rigid gas-permeable lenses. After having an eye exam, the physician might offer a suggestion, but most often, the decision is left to the consumer.

Definition

• Cornea

  Brochures in your opthamologist's office will tell you that the two main types of contact lenses are rigid and soft. Rigid lenses (formerly called "hard lenses") are made from various degrees of inflexible plastic. Although only about 25 percent of contact lens wearers choose these, the numbers are increasing, due to recent improvements made to these lenses. Soft contact lenses---smaller, thinner, and more flexible---contain a higher concentration of water with greater oxygen transmission and air flow to the eye.

Improvements

• The Division of Opthalmology and Visual Sciences at the University of Illinois at Chicago (UIC) states that the old-fashioned "hard contacts" fell out of fashion because little oxygen was able to flow through the rigid lenses, causing corneal swelling in some patients. Improved rigid gas-permeable lenses (RGP) were first made available in the 1980s. Improvements continue to be made.The most recent form are extended-wear versions of rigid lenses. About 98 percent of rigid-lens patients now wear gas-permeable lenses.

Advantages of both

• The new rigid gas permeable (RGP) lenses provide durable, inexpensive, non-allergic wear for patients with nearsightedness, astigmatism, or bifocal needs. People who have had past corneal diseases have successfully worn RGPs. Their rigidity provides clearer vision.

  Soft lenses require less time for adjustment and provide superior comfort, according to UIC. These inexpensive lenses are used for near and farsightedness, for some degrees of astigmatism, and for vision correction due to cataract surgery.

Disadvantages of both

• RGPs require a period of adjustment for comfort and then need to be worn on a regular basis. Vision is sometimes blurry when lenses are removed, even when replaced with glasses. These lenses don't contain as much water and are not available in disposable or extended wear varieties as soft lenses are. High water content in soft lenses necessitates monthly replacement due to proteins and lipids that adhere to them from your tears.

Summary

• Education about contact lens options and information gained from an eye exam and discussion with an eye care practitioner are imperative to your eye health. Further information can be provided by contacting the educational website of the Contact Lens Manufacturers Association.