here are basically two types of contact lenses:
1. Rigid Gas-permeable (RGP) Contact Lenses which are also known as "semi-soft lenses"
2. Soft Contact Lenses Hard Contact Lenses have become obsolete now.
Soft lenses can be further classified depending on the type of wear:
Disposable (Quarterly, Monthly, Fortnightly, Weekly and Daily)
There are certain steps you need to take to ensure that your eyes stay healthy and your contacts last as long as possible. For the exact care of your contacts, please refer to these articles:
Soft Contact Lens Care
Rigid Gas Permeable Contact Lens Care
The exceptions are daily disposable contact lenses and some extended wear contacts that are discarded every time they're removed. With these, you throw them out when you're done wearing them, so there's no care regimen at all.
That depends on how responsible the child is. This decision is best made jointly between you, your child and your eye doctor. Please see our Contact Lenses for Kids article for more information.
our eye doctor will prescribe your replacement schedule. It depends on the contact lens material and design, as well as your lifestyle and the condition of your eyes.
Each individual is different, although there are some broad guidelines that may be followed. If you are interested in initial comfort, soft contact lenses may suit you better than rigid gas permeable (RGP) lenses. On the other hand, RGP lenses tend to last longer. A soft (hydrophilic) lens is more appropriate for occasional wear (at most once or twice a week).
Not everyone can wear both types. Only after thoroughly examining your eyes and vision, can one advise whether you can wear RGP lenses, soft lenses or both. In your initial consultation, a number of tests and measurements will be performed, usually following a full, general visual examination. This evaluation will determine the optimum contact lenses for your specific needs. Additionally any other factors that determine your ability to wear lenses successfully will be explained to you.
Various general health factors, including medication, ocular, medical and family history will be assessed. A number of prescription medications, drugs and allergic factors can influence the ability to wear contact lenses successfully. Additionally your work and social environments can affect lens choice for example air-conditioning, computer use, dusty environments and so forth will affect the lens choice.
With normal use, contact lenses will stay firmly in position. However, they can come out under certain conditions. High winds can cause the eyes to water and pull the eyelid tight against the eye, increasing the chance of lens loss. A sharp blow to the head may dislodge rigid gas permeable lenses. And rubbing your eye carelessly may result in a lost lens.
Describe to your eye care practitioner all of the circumstances in which you are likely to wear your contact lenses. This will help him or her prescribe a type of lens that is less likely to be dislodged given your activities.
Pool water can cause discomfort due to chlorine. It is best to avoid swimming with your contact lenses on because it exposes your contacts to bacteria and other microorganisms in the water. These can adhere to your lenses and place you at risk of eye infections.
If you do swim with your lenses, you should wear goggles with a firm seal. If you don't wear goggles, the contact lenses may float from your eyes. They may also absorb the pool water, one consequence of which may be that they adhere quite firmly to the eye. If this occurs, it is advisable to leave the lenses alone for 10-15 minutes until your natural tears have replaced the water in them, before trying to remove them. You should then disinfect them immediately afterwards.
You're less likely to have success with contact lenses than someone who does not have this condition. This does not mean that you cannot wear contact lenses at all. It simply means you may have a shorter contact lens wearing period than normal or that you may choose to wear your lenses only occasionally. You can increase the comfort of your lenses by inserting eye lubrication drops.
For the same reason, wearing contact lenses while traveling by plane can be uncomfortable. The low humidity in aircraft cabins contributes to dry eye symptoms and contact lens discomfort. It may be helpful to put lubrication drops in your eyes before you enter the aircraft, or during flight. If symptoms persist or become severe, it is probably easiest and best to wear eyeglasses when flying. As always, it is best to consult your eye care practitioner for the best advice regarding whether you should wear contact lenses and what type of lenses may be suitable for such a condition.
While some cosmetics may interfere with contact lens performance and the wearer's tolerance for contacts, others are safe. Some rules should be followed when using cosmetics: Insert lenses before applying eye makeup and take them out before removing cosmetics. Use hair spray and other aerosols before lenses are inserted. Allow time for the aerosol mist to settle from the air or go to a different area before handling lenses.
Completely remove residual cosmetics from you hands with mild, additive-free soap before handling lenses.
Use cream shadows instead of powders and avoid using shadows with glitters.
Use water based cosmetic formulations.
Use hypo-allergenic cosmetics.
Avoid using mascaras containing fibers for extra lash length.
Avoid using saliva to wet applicators.
Don't apply eyeliners and pencils inside the upper or lower eyelid margin.
Normally the cornea is nearly spherically shaped thus allowing light to be focused clearly on the back of the eye (retina). However in a condition called Keratoconus, the cornea begins to thin, and this allows the normal pressure of the eye to make the cornea bulge forward taking on a cone-shape. As the cornea gradually becomes more cone-shaped, the vision blurs and becomes distorted. Initially vision may be correctable with spectacles, but as the condition progresses, and the cornea becomes more irregular causing distorted vision, spectacles become less effective. In such a situation, contact lenses not only provide better vision, but also help to retard the progress of the disorder. A rigid contact lens (RGP / "semi-soft" contact lenses) must be used, so that it can hold its shape, as a soft lens would simply mould to the existing shape and thus not allow complete correction of the problem. Sometimes the patient is fitted with soft lenses (for comfort), over which semi-soft lenses are fitted ("piggy-back" lenses). Recently special contact lenses called Rose K lenses have been devised which can be tailor-made to fit the "cone" in patients suffering from keratoconus. Fitting contact lenses for keratoconus requires expertise. A well-fitting contact lens dramatically improves such a patient's vision to nearly that of a normal person's, and significantly improves his or her quality of life. Any excessive pressure of a poorly fitting lens on the cone apex can cause permanent scarring within months or years (This scarring can also occur naturally). For this reason it is important for regular follow-up visits to be made so that any corneal changes that have occurred can be compensated for in the design of a new lens. It is quite common for patients to be refitted at irregular intervals as the condition progresses. Rarely, scarring is so severe that a corneal graft (transplant) is necessary.