Contact lenses are much more than a piece of plastic. They are an FDA regulated medical device that comes into direct contact with the delicate tissue of your eye. Without proper care and examination, contact lenses may lead to significant problems over time. To maintain optimal eye health, comfort and vision, we require all contact lens patients to have a comprehensive eye examination and a contact lens evaluation annually to renew their prescription.
Here is a list of what our doctors will examine during your annual contact lens evaluation.
1. Detailed corneal health evaluation under high magnification
The cornea is the transparent part of the eye that covers the front part of the eye. It's function is to refract light through the pupil so that it can enter our eye and land on our retina. The cornea is one of the most important structures for clear vision. Because contact lenses are in contact with the cornea during wear, they can cause some problems.
Contact lenses can cause the eye to get tiny scratches or missing cells that the doctor can see under the microscope. This can affect your vision, increase glare and make your eyes red and irritated. Keratitis can be caused by other factors as well such as dry eye, not cleaning your contacts properly and over wear of contact lenses. If Keratitis becomes serious, it can lead to an infection.
A poor fitting contact lens, over wear of contact lenses and contact lens infections may lead to corneal scarring, where areas of your cornea lose clarity. If the corneal scar forms over the pupil this can cause irreversible loss of vision, glare and halos and light sensitivity.
The cornea does not have blood vessels. It gets oxygen from the air while our eyes are open and from the blood vessels on the back the eyelid when our eye is closed. Wearing contact lenses can limit the oxygen that makes it to the cornea and cause new blood vessels to grow called neovascularization. These new blood vessels can cause corneal swelling which may change your prescription and cause the cornea to become hazy. You are at increased risk of this condition if you sleep in your contact lenses, over wear your contact lenses or wear outdated contact lenses that do not allow as much oxygen through the lens as the newer technology contact lenses.
2. Evaluation of size and parameters of contact lenses
Every contact lens patient will have specialized measurements known as keratometry taken of their cornea. This measures the curvature (steepness or flatness) of the cornea. This measurement is imperative for the doctor to determine the proper base curve and diameter of the contact lens. Eyes can grow and change shape over time and the doctor must evaluate if the contact lens fits properly against the tissue of your cornea to ensure the contact lens is:
Not too tight: therefore restricting tear and blood flow
Not too loose: causing irritation, loss of corneal cells and a foreign body sensation
3. Contact lens material evaluation
Over time, our eyes can develop a sensitivity to the contact lens material and coating. This sensitivity can lead to dry eyes, itching, discharge and redness and may cause a condition called Giant Papillary Conjunctivitis. The doctor will examine the tissue around your eye to check for beginning signs of this problem and may recommend switching contact lens brand or going to a daily disposable lens to avoid future issues.
4. Visual evaluation with the contact lenses
What is the point of wearing contacts if you don't see to your best
potential? Contact lens prescriptions are often different than glasses
prescriptions and may vary in power due to astigmatism or because
the contact lens rests on the surface of your eye. To ensure your
vision is as clear and comfortable as possible, an over-refraction
may be performed while wearing your contact lenses.
5. Reviewing and instructing on proper care of contact lenses
Sometimes even patients that have been wearing contact lenses for many years are not following
the proper steps to be as safe as possible. It is our priority that you experience optimal
comfort and confidence wearing contact lenses. The doctor and staff will make sure you have
all questions answered regarding insertion and removal techniques,
proper cleaning, care and disposal of your contact lenses.
RISKS OF CONTACT LENSES
As you see above, there are many things the doctor checks and considers at your annual contact lens evaluation. Contacts can cause irreversible damage to your vision. So please be careful with wearing contact lenses and always call us if you start to notice any problems right away!
The following issues that have been reported with the use of contact lenses:
Discomfort or feeling of something in the eye
Unusual eye secretions
Rainbows or halos around objects
Sensitivity to light