Contact lenses: A Consumers Guide


Those who want to wear contacts for the first time are faced with numerous questions: What is the first step? Who prescribe the contact lens? How can we diagnose a reverse lens in the eye? By reading this article, you will get useful information about these and other fields.


The First Step to Choose the Right Contact Lenses

If you're new to contact lenses, your first step is consulting an ophthalmologist or at least a qualified optometrist, and this includes the use of colored contact lenses even cosmetic ones. Why? Because contact lenses are a medical device that should properly be prescribed by an eye specialist. The ophthalmologist examines your eyes to make sure that you have no problems in wearing contact lenses and then will prescribe your contact lens.


Types of Contact Lenses

Contact lenses are classified by material characteristics, replacement frequency or wearing schedule.

Contact lenses are made from different types of plastic and are divided into two main groups: hard and soft. Soft lenses content 25 to 79% water, are quite comfortable, and have a very short adaptation period. Gas permeable lenses (Rigid Gas Permeable - RGP) have a longer adaptation period, are more durable and resistant to deposit buildup.

Gas permeable lenses are recommended for those who want a better vision quality. Contact lenses are also classified based on how frequently they should be discarded. RGP lenses can last a year or longer, but soft lenses are classified in terms of replacement time.

Extended wear can be worn overnight, and daily wear are worn only during the day and must be removed nightly.


New types of contacts

Lenses that can be used continuously for 30 days are a new generation of soft contact lenses called silicone hydrogels, which allow much more oxygen to pass through to your eye and are very safe and comfortable. Toric and bifocal lenses are other disposable types of lens that have recently been marketed.

UV-inhibiting lenses can be soft or hard. They protect your eyes from harmful UV radiation. Since these lenses are perfectly clear, and their UV blocking cannot be detected by looking at them, we should check what is written on their packages.

Of course, it should be noted that contact lens can only protect the cornea, and wearing UV-blocking sunglasses outdoors can protect your entire eye and the skin around, then the amount of protection from UV radiation can be increased by wearing contact lenses that block UV.

Other new lenses are lenses that reshape the cornea and correct your vision without wearing lens or undergoing a surgery. They are called orthokeratology; these lenses are worn overnight and removed during the day. They alter the shape of the cornea during the night, thereby without the need for contact lenses during waking hours, your eyesight improves.


Disposable Contact Lenses: A Healthy Choice

Disposable contacts are worn for a specific period of time, then thrown out and replaced with fresh lenses. Disposables were introduced in 1987 and have become the most common type of contact lenses.

Contact lenses generally fall into three categories:

  1. Disposable lenses: Replaced every two weeks, or sooner
  2. Frequent replacement lenses: Replaced monthly or quarterly
  3. Traditional lenses: Replaced every six months or once a year

Disposable contacts are either "Daily wear" or "Extended wear". Daily wear is only worn during the day and removed each night, but Extended wear is worn continually, including during sleep.


Why Should You Throw Away Your Contact Lenses on Time?

The more frequently you replace your contact lenses, the healthier and more comfortable your eyes can be. Protein, calcium, lipids and other substances found naturally in your tears can build up on your lenses. These deposits irritate your eyes, and can also make your eyes more prone to infection. Of course, you can always keep your lenses clean, but disposable contacts save your time. Some deposits will remain and continue to accumulate over time. One-day disposables, which are replaced every day, require no lens cleaning, and they are healthy because there is no day-to-day accumulation of lens deposits.


Which Contact Lens Replacement Schedules Is Right for You?

Lens replacement schedule depends on each individual's eye. Some people's eyes produce more protein and lipids than others, and their lenses may need to be replaced more often. However a thorough evaluation by your ophthalmologist can help determine the best replacement schedule for you.


Colored Contact Lenses

Colored contact lenses can be divided into the following kinds of tints:

  • Visibility tint
  • Enhancement tint
  • Opaque tint
  • Colored lens filters light
  • Light-filtering Tints

The tint (color contacts) may be used for cosmetic purposes only; they can also be used to correct astigmatism, presbyopia or refractive errors.

    Visibility tint: This usually is a light blue or green tint added to a lens, just to help you see it better during insertion and removal, or if you drop it. Visibility tints are relatively faint and do not affect your eye color.

    Enhancement tint: This is a translucent (see-through) tint that is a little darker than a visibility tint. Colored contacts with this type of tint usually are best for people who have light-colored eyes and want to make their eye color more intense.

    Opaque tint: color contacts with opaque tints come in a wide variety of colors that can change your eye color completely.

Companies that make colored contact lenses do their best to make these lenses as similar to your iris as possible; they even feature a series of tiny colored dots and radially arranged colored lines and shapes to help the lenses look more natural on the eye. The center of the lens, the part that lies over your pupil, is clear so you can see.

Light-filtering Tints have been recently produced, and are more used in sports fields to intensify certain colors, for example, a yellow filter makes tennis or golf ball more specific and easier to target in the field.


Some Disadvantages of Colored Contact Lenses:

Since companies produce different-sized lenses to fit most wearers, there will be some occasions, especially during blinking, where the colored portion may slide over the pupil. Also, the size of your pupil is constantly changing to accommodate varying light conditions, so at night your pupil may be larger than the clear center of the lens. In these instances, your vision may be affected slightly. Contact your eye doctor immediately if you experience discomfort while wearing your contact lens.


Why Sharing Contact Lenses Is a Bad Idea?

It is wrong to swap colors with your friends. Contact lenses are medical devices and are fitted to the specifications of each individual's eyes. Exchanging lenses also can transmit harmful bacteria, which can lead to eye infection. Color contacts must be properly cleaned and disinfected with antiseptic solution.

Do You Need a Prescription for Colored Contact Lenses?

All contact lenses, worn for any purpose, require a valid contact lens prescription written by a qualified eye care professional and cannot be sold to consumers without one.

Whether you wear contact lenses to correct your vision or only for cosmetic use, you definitely need to have a prescription. Since there is a high risk of blindness and damage to the eyes, it is better to consult an optometrist or ophthalmologist and refrain from buying lenses from markets, barbershops and....


Seven-day and 30-day Extended Wear Contact Lenses

Extended wear contacts are contact lenses that can be worn overnight (some contact lenses are daily wear- you remove them before sleeping). Extended wear lenses allow more oxygen to circulate and reach your cornea. Most of them are usable continuously for up seven days, and then should be discarded.

There are two types of contact lenses which are approved for 30 day continuous wear: Ciba Focus Night & Day and Bausch & Lomb PureVision.

However, lenses that are used on night have a greater risk of infection than daily wear lenses, because dangerous organisms which enter the eyes through fingers, eyelids, or contact lens solution grow better at night and increase the likelihood of corneal infection. Of course 30-day or 7-day replaceable lenses, because they do not require lens solution, reduce the amount of microorganisms' entry into the eye and do not enhance the risk of infection. The Continuous wear contact lenses, currently available on the market, are made out of highly permeable to oxygen silicone hydrogel. For example, "Night and Day" lens brings 6 times more oxygen to the cornea than conventional soft contact lenses.

It has been shown that smoking is an important risk factor in the complications of extended wear contact lenses.

To reduce the risk of eye infection, it is recommendable not to wear your contact lenses constantly. For instance, wear them only during midday naps or holidays and in other times remove them in bedtime; however there is an added risk in using lens solution and lens case.

Note that if your eyes become irritated, or you experience a reduction in vision, remove the lenses and contact your eye doctor straight away.


Gas Permeable Contact Lenses (RGP)

GP contact lenses are rigid, but they but they are different from old-fashioned hard contact lenses of previous decades. Hard contact lenses were, at first, made of a material known as PMMA and caused irritation because they were not oxygen-permeable.  Gas permeable contacts were first introduced in the mid 80's; they incorporate silicone, are more flexible than PMMA and transmit more oxygen to the eye than do traditional soft contact lenses.

GP lenses also provide better vision, durability, and deposit resistance than soft contact lenses. They are cleaned more easily and because they last longer than soft lenses, they can be less expensive in the long term. On the other hand, soft contact lenses are more comfortable, and GP lenses require an adaptation period.


Advantages of RGP Lenses

Gas permeable contact lenses offer some outstanding benefits over soft lenses. Because GP lenses are made from a firm material, they retain their shape when you blink, and tend to provide better vision than soft lenses.

GP lenses last for a long time. Although they are breakable (for instance, if you step on them), you can't tear them easily (unlike soft lenses), protein and lipids from your tears do not adhere to them, and with a little care, GP contact lenses can last for years.

GP contacts are a good choice for people who don't obtain acceptable vision with soft lenses and require a higher visual acuity, or people whose astigmatism is not correctable with soft contacts.

GP contacts are good for people who have keratoconus numerous, and there are various bifocal and multifocal GP designs to correct presbyopia. Recent studies have shown that the in children, wearing GP can slow the progression of myopia.


Disadvantages of GP Lenses

GP lenses require an adaptation period, so you need to wear them every day, while if you don't wear your soft lenses for a week, they'll still be comfortable when you put them on a week later.

Some people may have blurry vision after replacing their GP with glasses which is temporary. Compared to 30-day or daily disposable lenses, GP lenses need more time to clean because they should be rubbed with a finger to be cleared.


Soft Contact Lenses Care

How to Know If Your Contact Lens Is Inside Out:

To make sure that your contact lens is placed not inside-out in your eyes, put the lens on your finger in front of your eyes. If it forms a "U" – as in the picture- it's in the correct position, but if the lens forms a "U" with the top edges flared out, it's inside out.

It is very important to understand lens care not caring properly may cause infection which may even lead to blindness. Nowadays, the use of various multiple use solutions, and daily disposable lenses have made caring more easily. Before we get started, note that you should not switch care regimens without asking your eye doctor first, because some products are not compatible with your contact lens.


How to Clean Soft Contact Lenses:

  1. Wash your hands so that you don't transfer dirt and germs to your eye. Avoid moisturizing soaps, because they are not good for your contact lenses. Dry your hands with a lint-free towel or handkerchief.
  2. First remove one lens and clean it with the special solution. Some products require rubbing the lens, while by pouring some solutions on the lens all debris is cleaned.
  3. Rinse the lens again.
  4. Place the lens in a clean lens case and fill with fresh suitable disinfecting solution.
  5. Repeat all of the steps for your other lens.


Other Cares:

  1. Protein removal: Depending on the type of contact lenses you wear and the amount of protein your eyes deposit on your contacts, your doctor may suggest a product for protein removal. The longer you wear lenses, the more need to a protein remover, but disposable lenses usually don't need such cares.
  2. Eye dryness and irritation removal:  Use contact lens eye drops to lubricate and moisturize your eyes your lenses.
  3. Eye sensitivity and allergies removal: If you develop an eye allergy to the chemicals present in contact lens solutions, you should use "preservative-free."


Different Disinfecting, Cleaning, and Rinsing Solutions:

  1. Saline solution: It is for rinsing and storing contact lenses, if you use a heat or UV disinfection system. Never use saline products for cleaning and disinfection. You also may need it if you use enzymatic cleaning tablets or disinfecting devices.
  2. Daily cleaner: It is for cleaning contact lenses. You place a few drops of it in the palm of your hand and carefully rub the lens, usually around 20 seconds, you should make sure that both sides are cleaned. Then use other products for rinsing and disinfection.
  3. Multipurpose solution: It is for cleaning, rising, disinfecting and storing your contact lenses. All are done with one solution; you can store lenses in the clean lens case with the same solution and when you want to wear your lenses, rinse them with this solution and insert them in your eyes.
  4. Hydrogen peroxide solution: It is used for cleaning, disinfecting, rinsing and storing contact lenses. With this product, first you place your lenses in the special basket and rinse them, then place the basket in its special cup and fill the cup with this solution to clean the lenses. Hydrogen peroxide solutions must have a neutralizer, whether built-in or by adding a neutralizing tablet so that hydrogen peroxide will be converted to water and won't cause sensitivity reactions. After removing the lens out of hydrogen peroxide solution, rinse it with another type of solution then insert it to your eyes.
  5. Cleaning and disinfecting devices: They use either ultrasonic waves or heat.  First rinse the lenses, then put them in the device and fill it with the solution. Plug the device in to clean and disinfect your lenses.
  6. Enzymatic cleaner: It is used for removing protein from contact lenses. They are usually used once a week. First clean and rinse your lenses, then fill your lens case with the solution. Drop one enzymatic tablet into the case and wait until it is dissolved, and then add your lens. Lenses should stay in this solution for usually 15 minutes. Afterward, disinfect your lenses with another solution.
  7. Daily protein remover:  It is in liquid form and uses daily. It can be used with multipurpose solution. First clean and rinse your contacts. Fill your lens case with multipurpose solution, then add a drop of daily protein remover to it and disinfect your lenses as usual.
  8. Eye drops:  They are used to moisturize the surface of eyes and lubricate your lenses. .
  9. Products for sensitive eyes: If you have allergic reactions to contact lens solutions and show symptoms such as itching, tearing, foreign body sensation, redness and eye discharge, you should see your eye doctor to determine the causes.

A preservative called thimerosal causes such reactions in about 10 percent of patients; however, people who have reactions to thimerosal can switch to thimerosal-free saline. Hydrogen peroxide, having neutralizer, usually don't cause such reactions.


What You Need to Know About Contact Lenses Hygiene:

  1. Never touch solution bottle tips to any surface, including your hands or face.
  2. Avoid rinsing your contact lenses under tap water because your lenses may get infected.
  3. Clean your contact lens accessories, specially your lens case with hot water and dry it in open air.
  4. Throw out your contact lens case once a month, and use a new one to reduce your risk of infection.
  5. Clean and disinfect your lens once a day to have a healthier eye and feel more comfortable while wearing your lens.


RGP or Hard Contact Lens Care

In general, hard lenses or RGP, made from a combination of fluoride and silicon, are easier to tend than soft lenses and more resistant to proteins and other deposits.

Of course the more years we use RGP, the more difficult is the process of its cleaning. When we cannot clean RGP with conventional cleaners, we should polish it.

In general, to clean a hard lens, rub it gently with your index finger and cleaning solution, then rinse it and put it in its case filled with storage solution. It is better to use storage solution than tap water. You can use enzymatic cleaner if there are lots of protein deposits on the lens. If you wear your lens in daytime and remove it in bedtime, use enzymatic cleaners only once a week. You may use rewetting solutions to lubricate your lens whenever you want to wear it. It is better to clean, rinse, and air-dry your lenses case after each use. Some care solutions designed for soft lenses cannot be used on GP lenses. Do not change solutions or use a not recommended product by your own opinion.


How to Handle Contact Lens Discomfort

If you feel discomfort with your contact lenses, you're not alone. Many people experience contact lens discomfort.  You need to see your eye doctor to determine the causes of this discomfort, as there may be various reasons for it.

If your eyes are red, painful, swollen or produce discharge, stop lens wear immediately and consult your eye care, because these could be signs of a serious problem.

Some medical problems, such as allergies, Sjogren's syndrome, thyroid conditions, hormonal changes brought on by menopause, and skin conditions such as acne rosacea, can cause vision problems or eye irritation, especially irritation from dryness.

Dry eyes are also a common side effect of many over-the-counter and prescription medications, such as antihistamines or blood pressure medications. Dry eye syndrome is a condition that can cause your eyes to feel gritty or appear red.

The coordination and harmony between eye and contact lens is very important, it means a lens that is well placed in a safe environment works properly. Problems such as allergies and diseases such as Sjogren's, thyroid problems or hormonal changes during menopause may cause eye problems such as eye irritation especially due to dryness of the eye. Artificial tears without preservatives can eliminate these symptoms, but make sure to use these drops with an ophthalmologist's prescription.

Nutrition is also an important factor because tear contains many compounds and your food affects the composition of your tears. If you drink lots of caffeine and alcohol and not enough water, your tears will become very dry and it is not good for contact lenses. By dietary supplements or changes in the diet, you can improve the oily part of your tear composition. For example, by consumption of omega-3 fatty acids in fish, you can regulate the amount of lipid in your tear, consequently tear evaporation will decrease.


Effects of the Type of Contact Lenses on Their Comfort or Discomfort

Nowadays, various types of contact lenses are available. Newer options are more comfortable than older lenses. Newer materials and newer designs make better choices for patients. .For example, silicone hydrogels allow more oxygen to reach the eyes and brings more comfort. The size and shape of the contact lenses is also important, especially if the diameter and radius of curvature of the lenses is not properly chosen, you will feel discomfort.


Proper Wearing and Caring Schedule for Contact Lenses

Patients' discomfort may be a result of not cleaning or disinfecting their lenses properly. Also the type of solution is important, because some solutions do not clean your lenses completely and little by little change the quality of lenses. So consult your eye doctor before switching the solution. Solutions containing preservatives may gradually develop sensitivity to preservatives.


Environmental Factors That Causes Contact Lens Discomfort

If you are working in a contaminated environment, waste is simply placed between your lens and your eye and cause discomfort. If you feel discomfort outdoors or around animals, allergy is a likely cause. Smoking increases the risk of dry eye and also overuse of the computer, due to reduced blinking, is another reason for experiencing dry eye.

However, even if there is slight discomfort, see your doctor to determine the cause.