Should I Consider Contact Lenses?

The vast majority of people requiring vision correction can wear contact lenses without any problems.  New materials and lens care technologies have made today’s contacts more comfortable, safer and easier to wear.

Advantages

• Many wearers feel that contact lenses show their eyes in a better light.
• Better vision correction due to the reduced obstruction from eyeglass frames.
• Less hassle than glasses

Disadvantages

• Contact lenses require getting used to.  New soft lens wearers typically adjust to their lenses within a few days.  Rigid lenses generally require a longer adjustment period.
• Except for some disposable contacts, most lenses require regular cleaning and disinfection.

For those involved in sports and recreational activities, contact lenses offer a number of advantages.  In addition to providing good peripheral vision, eliminating the problem of fogged or rain splattered lenses, and freeing you from worries about broken glasses, contact lenses also mean you can wear non-prescription protective eye wear.

Looking sideways through the lenses of glasses leads to prismatic effects because you are not looking through their centers.  Your eyes have to coordinate differently to cope with this.  This does not happen with contact lenses because you always look through the centers of the lenses as they move with your eye movements.

Your occupation and work environment should also be taken into consideration.  People whose work requires good peripheral vision may want to consider contacts.  Those who work in dusty environments or where chemicals are in heavy use are likely to find spectacles more comfortable.

Consider the questions and answers below to help assess whether they’re a choice you should consider.

Contact lens wear may be difficult if:

• Your eyes are severely irritated by allergies
• You work in an environment with lots of wind, dust and chemicals
• Your eyes are overly dry

After a thorough eye examination, your suitability for contact lenses and the specific contact lens option that best meets your personal needs will be determined and discussed with you.

How Do Contact Lenses Correct My Vision?

Contact lenses are designed to rest on the cornea, the clear outer surface of the eye.  They are held in place mainly be adhering to the tear film that covers the front of the eye, and, to a lesser extent, by pressure from the eyelids.

As the eyelid blinks, it glides over the surface of the contact lens and causes it to move slightly.  This movement allows the tears to provide necessary lubrication to the cornea and helps flush away debris between the cornea and the contact lens.

Contact lenses are optical medical devices, primarily used to correct nearsightedness, farsightedness, astigmatism and Presbyopia.  In these conditions, light is not focused properly on the retina, the layer of nerve endings in the back of the eye that converts light to electrochemical impulses.  When light is not focused properly on the retina, the result is blurred or imperfect vision.

When in place on the cornea, the contact lens functions as the initial optical element of the eye.  The optics of the contact lens combines with the optics of the eye to properly focus light on the retina.  The result is clear vision.

The Different Types of Contact Lenses

Contact lenses may be identified by the type of refractive error they are designed to correct.

• Spherical contact lenses for nearsightedness and farsightedness
• Toric contact lenses for astigmatism
• Bifocal lenses for Presbyopia, the loss of ability to focus on reading or close-up activities

As an alternative to special bifocal contact lenses, many practitioners use a system called monovision where one eye is fitted with a distance lens and the other with a reading lens.  Approximately two-thirds of patients adapt to this type of contact lens wear.

Contact Lens Wearing Schedules

Daily or Extended Wear Contacts

Daily Wear:

Lenses prescribed for daily wear are to be worn only during waking hours, usually up to a maximum of 18 hours.

Daily wear lenses are removed at night and cleaned and disinfected after each removal.

Extended Wear:

Extended wear lenses may be worn on an overnight basis for up to seven consecutive days (six nights).  You should wear you lenses on an extended wear basis only on the advice of your optometrist.

Extended wear lenses generally have a higher water content or thinner center thickness than other lenses and permit more oxygen to reach the eye.  However, their use has been linked to a higher incidence of eye problems.

Extended wear lenses must be cleaned and disinfected at recommended intervals per the manufacturer’s instructions.

Contact Lens Cleaning Solutions

When you are fitted for contact lenses, a particular lens care system will be recommended to you that will clean, disinfect and make your lenses safe and comfortable to wear.

Since different systems use different types of chemicals, it is not advisable to mix or substitute solutions from other systems.  Doing so could lead to discolored lenses, eye discomfort or eye injury.  In particular, rigid lens solutions should not be used to clean or disinfect soft lenses as the chemicals can damage the soft lens material.

Soft Contact Lens Care Systems

Regardless of how they are packaged, most lens care systems include products that perform six different functions.  Some systems combine two or more functions into one product while others keep them separate.  The functions required are dependent upon the type of lens regimen and your eyes and will be discussed with you as a part of a contact lens training program.

The different functions performed by soft lens care systems are:

• Daily Cleaning to remove debris accumulated and adhering loosely to the lens.  This debris, if not removed, can eventually make the lenses uncomfortable, interfere with vision and reduce the ability of the disinfecting solution to kill potentially harmful microorganisms.  In addition, the cleaning solutions perform the first stop in the disinfection process.
• Disinfecting to kill growing forms of microorganisms (bacteria, fungi, and viruses) on the lenses.
• Rinsing and Storing requires the use of an ophthalmic isotonic saline solution or may be performed with some types of disinfectant solution.  Most saline solutions are not suitable for the storage of lenses, as they do not contain anything to kill or prevent the growth of microorganisms.
• Comfort or Lubricating Drops are used to provide refreshment for dry eyes, in conditions of low humidity or for added comfort near the end of the wearing day.
• Protein Removal removes stubborn protein deposits and, with daily cleaning and disinfection, helps restore a clean, fresh contact lens surface.  Protein removal is generally not required for planned replacement lenses, which are replaced before the deposits can cause difficulties.

Contact Lens Wear and Care Recommendations

The information below is intended as a supplement to the training and instruction you receive as part of a contact lens fitting program.

How to Insert and Remove Your Contact Lenses

Preparation

• Wash your hands with a mild soap, rinse completely and dry with a lint-free towel.  A wet finger may cause a soft lens to flatten.  Avoid using fingernails to handle your lenses.
• If you’re working near a sink, close the drain.
• Get in the habit of always working with the same (right or left) lens first to avoid mix-ups.
• Pour the lens and storage fluid from the case into your palm.
• Inspect the lens for particles, deposits or tears.
• Place the lens, cup side up, on your dry forefinger.  Determine if the lens is right side out.
  • If it is right side out, the lens’ edge will appear almost straight up.  If inside out, the edges will flare out slightly.
  • Another test is to place the lens on a crack in the palm of your hand and then cup the hand slightly.  This will flex the lens.  If the edge of the lens curls inwards, it is the correct way out; if the edge curls outwards and wraps onto the palm of the hand, it is inside out.  If it is inside out, reverse it.

How to Insert Contact Lenses

• Hold the upper lashes (or lids) to prevent blinking.
• Pull the bottom eyelid down using your middle finger.
• Look up so the white part of your eye shows.
• Place the lens onto the exposed white part of your eye.
• Or, instead of looking up, look straight ahead at the lens and gently place it in the center of your eye.
• Remove your finger and let go of the lids, bottom lid first, and then top.
• Look downward to help position the lens, and then close your eyes momentarily.
• Apply one or two drops of lens lubricant (eye drops) if your lenses feel dry or if blurry vision occurs during wear.
• Follow the same steps to insert the other lens.

How to Remove Contact Lenses

• Wash and dry your hands and close any nearby drains.
• With your head straight, look upwards as far as you can.
• Place our middle finger on the lower eyelid of your right eye and pull the eyelid down, then touch the lower edge of the lens with the tip of your index finger. 
• While still looking up, slide the lens down to the white part of the eye with your index finger.
• Still looking up and holding the lens under the index finger, move your thumb so that you can compress the lens lightly between the thumb and the index finger.  Then gently remove the “folded up” lens from the eye.
• If you have difficulty removing the lens, place a few comfort drops in the eye, wait a few moments and then try again.
• Remove the left lens following the same procedure.

Follow Professional Advice

• Wear your contacts only for the length of time recommended, even if they feel comfortable.
• Remove, clean and disinfect your lenses at the intervals prescribed.
• Have regular check-ups.
• Don’t sleep or nap while wearing your contacts unless specifically indicated.
• Don’t use any eye medications without consulting the doctor.

Make Cleanliness a Habit

• Before touching your lenses, wash your hands thoroughly with a mild soap, rinse completely and dry with a lint-free towel.
• Apply eye cosmetics after you insert your lenses. Remove cosmetics after you remove your lenses.  Water-based cosmetics are less likely to damage lenses than oil-based products.
• Avoid excessive handling of your lenses.
• Protect your solutions from contamination:  Close bottles tightly and never touch the dispensing spouts to any surface.
• Never re-use solutions.
• Ensure that tap water never comes into contact with soft lenses.
• Do not get lotions, creams or sprays in your eyes or on your lenses.
• Avoid wearing lenses in the presence of chemicals, unusual air pollution, intense heat (hair dryer) or when swimming.
• Throw away disposable and frequent or planned replacement lenses after the recommended wearing period.
• Don’t use expired products.
• Never skip steps in lens care.  Cleaning is not enough.

Replacement Schedules

Replacement Period

Contact lenses are often prescribed with a specific replacement schedule suitable to your specific needs.  Planned (or Frequent) Replacement contacts are disposed of and replaced with a new pair according to a planned schedule:  daily, one to two week, monthly or quarterly.

Unplanned replacement lenses (often called conventional lenses) are not replaced according to a pre-determined schedule.  They are typically used for as long as they remain undamaged, usually around 12 months for soft lenses.  Interest and demand for conventional lenses has dropped significantly over the past several years as the cost of replacing your lenses more frequently has come down significantly.