Contact Lens Types
There are three types of contact lenses, classified by the materials they are made from:
- Soft lenses – Made from a gel-like, water-containing plastic, these are the most common type of lenses and are slightly larger in size than your cornea.
- Hard lenses – Made from rigid plastic called PMMA that does not transmit oxygen to the eye, these lenses have virtually been replaced by GP lenses and are rarely prescribed today.
- GP lenses – These are oxygen permeable lenses, meaning they are made from rigid, waterless plastics and are especially good for presbyopia and high astigmatism. GP lenses are smaller in diameter and often provide sharper vision than soft lenses.
Bifocal Contact Lenses
- Bifocal contact lenses have two prescriptions in the same lens allowing different focus zones for near and far sighted correction.
- Bifocal contact lenses are designed to provide good vision to people who have presbyopia, a condition where the eye exhibits a progressively diminished ability to focus on near objects as a result of aging. The first signs of which are often difficulty seeing in dim light, problems focusing on small objects and/or fine print –usually first noticed between the ages of 40 and 50.
- Bifocal contact lenses come in both soft materials and GP materials. Some can be worn on a disposable basis. That means you have the convenience of throwing the lenses out at specified intervals (even daily, in some cases) and replacing them with fresh, new lenses.
Toric Contact Lenses
Toric contact lenses are made from the same materials as regular ("spherical") contact lenses, so they can be either soft or GP. The difference is in the design of the lens.
Toric lenses have two powers, created with curvatures at different angles (one for astigmatism, the other for either myopia or hyperopia). There's also a mechanism to keep the contact lens relatively stable on the eye when you blink or look around.
Colour Contact Lenses
- Coloured contact lenses are available in 3 options: visibility tints, enhancement tints and opaque color tints.
- Coloured contact lenses are available in plano (for cosmetic purposes), as well as designs for people who need prescription contact lenses. Most coloured contact lenses are disposable.
Remember it is advisable to have your eyes tested before wearing cosmetic or prescription contact lenses.
Do not purchase contact lenses from any other outlet other than a professional eye care practitioner.
Silicone Hydrogel Contacts
Silicone hydrogel contact lenses represent a breakthrough over traditional hydrogel soft contact lenses, because silicone allows much more oxygen (essential for a healthy cornea) to pass through the lens.
Disposable Contact Lenses
Disposables have become the most popular type of contact lenses which are worn for a specific period of time, then thrown away and replaced with a fresh pair.
Types of disposable contact lenses:
- Daily - Discard after a single day of wear.
- Weekly - Discard every two weeks, or sooner
- Monthly - Discard monthly or quarterly
- Reusable - Discard every six months or longer
All of these lenses, except the daily disposable lenses, need to be removed and cleaned every night.
Extended wear contact lenses may be the right option for you if you would like to wake up each day with clear vision. Most extended wear lenses can be worn without removal for up to seven days.
Which Contact Lenses are right for you?
First, your contacts must address the problem that is prompting you to wear lenses in the first place.
Your Spec-Savers optometrist is skilled in evaluating which lenses will best satisfy your prescription. He or she will also consider convenience, colours and extended wear to best suit your needs.
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