Contact Lens
Contact lenses are thin, clear disks of plastic that float on the surface of the eye.
- Contact Lenses for Vision Correction
- Contact Lens Types
- Important Things to Know About Contact Lenses
- Proper Care of Contact Lenses
- FAQs
- Other types of Contact lens
Contact Lenses for Vision Correction
Millions of people around the world wear contact lenses. When used with proper care and maintenance, contact lenses may provide a safe and effective alternative to eyeglasses. They correct vision like eyeglasses and are safe when used with care. Contact lenses are used to correct the same conditions that eyeglasses do i.e. myopia (nearsightedness), hyperopia (farsightedness), astigmatism (blurred vision due to the shape of the cornea) and presbyopia (inability to see close up).
Contact lens types
There are two general types of contact lenses: hard and soft.
The hard lenses most commonly used today are rigid, gas-permeable lenses (RGP). They are durable, resist deposit build up, and generally allow for clear, crisp vision. They last longer than soft contacts, and also are easier to handle and less likely to tear. However, they may take a few weeks of getting used to.
Soft lenses are the choice of most contact lens wearers. These lenses are comfortable and made of flexible plastic that allow oxygen to pass through the cornea. Daily-wear lenses are the least expensive, are removed every night and are replaced on an individualized schedule. They should not be used as an extended-wear lens.
Extended-wear lenses are worn overnight but are removed at least weekly for thorough cleaning and disinfection. They are recommended less frequently, since there is a greater risk of corneal infection.
Important Things to Know About Contact Lenses
- Lenses that are not properly cleaned and disinfected increase the risk of eye infection. Any lens that is removed from the eye needs to be cleaned and disinfected before it is reinserted.
- Care of contact lenses includes cleaning their case, since it is a potential source of infection. The case should be rinsed with contact lens solution and allowed to dry.
- Lenses that are old or not properly fitted may scratch the eye or cause blood vessels to grow into the cornea. Because a lens can warp over time, and the cornea can change shape, the fit of the contact lens and the power should be re-evaluated on a regular basis.
- You may not be a good candidate for contacts if you have:
- Frequent eye infections;
- Severe allergies;
- Dry eye that is resistant to treatment;
- A very dusty work environment
- An inability to handle and care for the lenses.
- Any eyedrops you use can interact with all types of contact lenses. It is best to avoid the use of eyedrops while wearing lenses, except for wetting drops recommended by your eye doctor.
- Homemade saline (salt water) solutions have been linked to serious corneal infections and should not be used.
- Disposable-wear lenses are more expensive, but convenient. They are removed nightly and replaced on a daily, weekly or monthly basis. Disposable lenses are sometimes recommended for people with allergies and for those who tend to form deposits on their lenses.
- Cosmetic or decorative contact lenses are coloured contacts that change the appearance of your eye colour. Cosmetic lenses are available by prescription and should only be worn after an eye exam and fitting by qualified eye care professional.
- Toric soft contact lenses can correct astigmatism, but sometimes not as well as RGP lenses do. They usually cost more than other contact lenses.
- Bifocal or multifocal contact lenses are available in both soft and RPG varieties. They can correct nearsightedness, farsightedness and astigmatism in combination with presbyopia. Cleaning and disinfection are specific to the lens material. Visual quality is often not as good as with single vision lenses; however, for some people the ability to correct presbyopia is worth it.
Proper care of Contact Lenses
While contact lenses are safely used by millions of people every day, they do carry a risk of eye infection. Factors contributing to infection can include:
- Use of extended-wear lenses;
- Reduced tear exchange under the lens;
- Environmental factors;
- Poor hygiene.
The single best way to avoid eye infections is to follow proper lens care guidelines as prescribed by your eye care professional. In particular, including a “rub and rinse” step in the lens cleaning process, minimizing contact with water while wearing contact lenses and replacing the lens case frequently can help reduce the risk of infection.
Taking Care of Your Lenses
The following guidelines for care of contact lenses have been developed
Risk of infection varies somewhat depending on the type of contact lens. Single-use daily disposable lenses are the safest type of soft contact lens, in terms of reducing the risk of infection. Rigid gas permeable lenses are a safer alternative than any type of soft contact lens. Your ophthalmologist can help you decide which type of lens is right for you.
Lens Care Tips
- Always wash and rinse your hands thoroughly before you handle your lenses.
- To avoid getting your lenses mixed up always apply (or remove) your lenses, one at a time in the same order.
- Contact lenses should not be rinsed with or stored in water (tap or sterile water).
- Never use eye drops or solutions that are not specifically for contact lenses
- Don’t use saliva to try and wet or clean your lenses. Saliva is not a sterile solution.
- Don’t sleep with your lenses on.
- Clean, rinse and disinfect your lenses every time you remove them.
- Keep all your solution bottles tightly capped when you are not using them.
- Don’t let the tip of solution bottles touch any surface [including your fingers or lenses
- Never use expired lens solution.
- Never reuse lens solution.
- Rinse your lens case every day with lens solution and not water and let it air dry.
- Replace your lens case every three months [or more frequently
- Do not let cosmetics like soap, make up, or sun screen touch your lens.
- Never wear your lenses when you’re going to be around irritating fumes or vapours [paint, hair spray, oven cleaner etc…..].
- Do not swim or go in a hot tub while wearing your lenses.
- Cracked or chipped lens should never be worn.
- During cleaning, rub your contact lenses with your fingers, then rinse the lenses with solution before soaking them. This "rub and rinse" method is considered by some experts to be a superior method of cleaning, even if the solution you are using is a "no-rub" variety.
Handle your contact lens solution with care:
- Do not re-use old solution or "top off" the solution in your lens case.
- Do not transfer contact lens solution into smaller travel-size containers. This can affect the sterility of the solution, which can lead to an eye infection.
- Do not allow the tip of the solution bottle to come in contact with any surface, and keep the bottle tightly closed when not in use.
- If you store your lenses in the case for an extended period of time, consult the instructions for the lenses or the contact lens solution to determine if re-disinfecting the lenses is appropriate before you wear them. In no case should you wear your lenses after storage for 30 or more days without re-disinfecting.
Some experts recommend that if you use contact lenses occasionally, you consider using single-use daily disposable lenses.
Taking Care of Your Eyes
Eye infections can lead to serious vision loss in some cases. Proper care of your eyes is just as important as proper lens care.
- Remove the contact lenses and consult an ophthalmologist immediately if you experience symptoms such as redness, pain, tearing, increased light sensitivity, blurry vision, discharge or swelling.
- Get regular eye exams. If you wear contact lenses, you should be examined by an eye care provider annually, and more often as needed.
Frequently asked questions
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. In few therapeutic conditions RGP lenses are only option.
A soft lens is more appropriate for occasional wear. Often daily disposable lenses are the most convenient – no solutions and cases to bother with.
Only if you’re wearing goggles with a firm seal. If you don’t wear goggles, the contact lenses may float from your eyes and also exposing your contacts to pool water places you at risk of discomfort due to chlorine and infection.
As soon as the need for vision correction is identified, contact lenses are a viable option. In fact, they have frequently been used in premature infants, who sometimes have vision problems. With proper care and lens maintenance, infants, young children, teens, and adults of all ages can wear contacts successfully.
Unlike glasses, contacts offer athletes a competitive advantage because they stay in place under dynamic conditions, provide a wider vision field, and eliminate the risk of glasses-related injuries. Contact lenses also make it easy to wear protective goggles.
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 instilling lubricating drops in your eye.
Growing number of people now wear disposable soft lenses, which can be worn for either a single day or up to seven, depending on the wear schedule prescribed by the eye care professional. Disposable lenses are usually prescribed in multi-packs, providing several weeks supply at a time.
Yes, you can. Put in your contact lenses before applying makeup. Always wash your hands thoroughly before touching your contacts.
Most first time wearers are delighted with the level of comfort that contact lenses provide. Initial contact lens fittings by professional eye care practitioners can minimize or eliminate any irritation associated with new lenses. After a brief adjustment period, most people report they can no longer feel contact lenses on their eyes.
Other types of Contact Lens
- Prosthetic Contact Lenses.
- Keratoconus Lenses: Rose-K2, piggy back
- Scleral Lenses.
- MultiFocal Contact Lens.
- Bandage Contact Lenses.
Prosthetic contact lenses
With this lens, one seeks to match the fellow eye. A perfect eye match cannot be achieved. The wearer has to accept small differences between the two eyes.
- Corneal opacities and corneal scars
- Cataracts – hypermature and traumatic
- Microphthalmos
- Aniridias (Absence of iris)
- Irregular pupils
- Albinism
- Corneal dystrophy
Scleral contact lenses:
Scleral contact lenses (ScCLs) predate rigid corneal and hydrogel lenses by seven decades, but still have a unique clinical role.
- Corneal ectasia
- Post Corneal transplant
- Corneal trauma or postsurgery
- Therapeutic or protective applications (Stevens Johnson Syndrome or ocular cicatrising pemphigoid)
- Cosmetic shells (Prosthetic Purpose)
