A contact lens is a corrective lens placed on the cornea of the eye to improve vision problems such as farsightedness, nearsightedness, astigmatism and presbyopia. An estimated 125 million people use contact lenses worldwide.
Types of Lenses:
Soft Contact Lenses:
The most common option for contact lens-patients is soft contact lenses. These lenses are made of hydrophilic or “water-loving” polymer. The oxygen-permeable soft lenses allow for comfortable extended periods of wear. Their comfortability combined with their ability to provide clear, stable vision makes soft contact lenses the popular choice. However, soft contact lens do not correct all vision problems, the vision obtained from them is not as sharp as with other lenses, and they tend to soil easily, and therefore need to be replaced more often.
Rigid Gas Permeable Contact Lenses:
Another option is the rigid gas permeable (RGP) contact lens. These contacts are made from rigid waterless polymer, and are oxygen permeable. RGPs transmit more oxygen to the eye than soft contact lenses, and therefore promote good ocular health. RGPs are generally prescribed to patients with irregular ocular surfaces, astigmatism not corrected by soft lenses, and to those patients who require a multifocal or bifocal lenses. They are longer lasting, easier to clean, and usually provided better vision than soft lenses. However, RGPs tend to slip off the center of the eye more easily, tend to collect debris under them more than soft lenses, and must be worn consistently at length to promote adaptation.
Cosmetic Contact Lenses:
Cosmetic contact lenses are lenses designed to alter the appearance of the eye. They may or may not also provide corrected vision. One type of cosmetic lenses aims to “change” the color of the eye by providing a tinted color to the lens, that when placed on the cornea gives the appearance of the desired color. Another type of cosmetic lens aims to give the appearance of an enlarged iris. Cosmetic lenses generally cause eye irritation when first introduced to the eye, but once adaptation occurs, irritation usually subsides.
- Unlike glasses, which tend to interfere with sports and exercise, contact lenses do not. This allows you more freedom to engage in any activity you want without worrying about your vision.
- Contact lenses generally offer better improved sight than glasses.
- For patients concerned with physical appearance, or the social stigma of wearing glasses, contact lenses offer an invisible option for improving vision.
- One of the main disadvantages of choosing contacts is that unlike glasses, contacts require consistent care. Each night, contacts must be removed from the eye, cleaned in approved solution, and placed in their airtight container. The container must be replaced every 3-6 months, and kept dry when not in use. Failure to adhere to proper cleaning procedures could lead to infection.
- The risk of infection is another disadvantage of contact use. Excessive wear of the lenses, particularly overnight wear, is associated with many safety concerns, and could lead to infections in the eyelid, conjunctiva, and cornea. Bacterial infection resulting from improper cleaning of lenses should also be a considered risk. Be sure Drs. Carey, Lally, Hewes, Rutti, Warner or Zheng reviews proper care for your contacts at the time of your appointment.
Eyeglasses are frames bearing lenses worn in front of the eyes, usually for the purpose of vision correction or ultraviolet (UV) ray protection. Glasses are generally supported by pads on the bridge of the nose and by arms placed over the ears.
Types of Glasses:
Modern eyeglass lenses are usually made from plastic such as polycarbonate and CR-39, which reduces the likelihood of breakage typical of glass lenses. They are also much more lightweight than glass lenses, and offer scratch-resistant coatings, as well as anti-reflective coatings to reduce glare. Drs. Carey, Lally, Hewes, Rutti, Warner or Zheng will help you determine which lens option is best for your eye’s needs.
There are also many fashionable styles of frames available today, reducing the self-consciousness that may be experienced by bespectacled patients.
Corrective lenses are used to treat refractive errors of the eye, such as farsightedness or nearsightedness, by modifying the effective focal length of the lens in order to alleviate the effects of these vision impairments. Correcting vision is accomplished by using lenses to move the focal point on the retina to each patient’s particular needs. The depth of the curve, the thickness of the frames, and the precise shape of the lens can all be used to change the focal point. These adjustments will be able to correct astigmatisms and presbyopia, as well as far and nearsightedness.
Sunglasses are made with darkened lenses to provide the eyes with protection against bright visible light, as well as UV light. Sunglasses can be made with either prescription or non-prescription lenses, so that even patients who rely on glasses can see clearly and safely in the sun. Sunglasses are important protection for your eyes, as exposure to sunlight can cause ocular problems such as cataracts, pterygium, and some kinds of eye cancer.
Bifocals, Trifocals, and Progressive Lenses:
As people age and their ability to focus worsens, they may decide to use multiple-focus lenses, which can be bifocal or even trifocal. Traditional multi-focal lenses have two or three viewing points, for example for distance and for reading, that patients can use depending on need. Modern developments, such as progressive lenses, provide a seamless transition between these different focal points.
- Whereas contact lenses present risks such as infection, glasses are a completely risk-free way to correct vision. Eyeglasses also may be used in place of safety goggles.
- Glasses are easy to maintain, needing only to be updated when the prescription changes. Contacts, on the other hand, require strict cleaning procedures, and must be replaced often.
- Some patients, especially adolescents, may feel self-conscious when they first learn they need glasses. The social stigma associated with wearing glasses can be a turnoff. However, the proper selection of a flattering frame, combined with the improved vision and minimalized headaches associated with straining and squinting, should ease some of the initial insecurity.
- A main disadvantage associated with glasses is that they hinder the patient’s ability to engage in certain sports or activities. However, advancements have made so that corrective lenses can be added to work masks or sports goggles to aid vision with minimal interference to activity.