WHAT IS DRY EYE?
Dry eye occurs when the normal flow of tears over the eyes is interrupted, or the tear film is abnormal.
HOW ARE TEARS INVOLVED?
Tears are one of the body's natural mechanisms of defense. They are produced by the lacrimal glands in the eye and secreted to coat, protect and nourish the ocular surface.
Tears carry essential vitamins and nutrients across the surface of the eye. They also act as a shield against damaging factors such as wind, heat, smog or foreign particles. Normally, every time you blink, you add another protective coating of tears over the eyes.
WHAT ARE THE SYMPTOMS OF DRY EYE?
Dry eye symptoms can include one or more of the following conditions:
Burning and stinging
Scratchiness, grittiness or a "foreign body" sensation
Sensitivity to bright light (photophobia)
Mucous secretions in the eye (mattering)
WHAT CAUSES DRY EYE SYMPTOMS?
There are a number of factors that can lead to dry eye. These include:
Reduction or loss of your eyes' ability to manufacture tears
Reduction or loss of the ability to blink adequately to fully coat the eye with tears
Preservatives contained in some bottled products for use in the eye, such as eyedrops or artificial tears. Frequent use of these products can aggravate dry eye conditions.
Wearing contact lenses
Consult your doctor to determine the possible causes for your particular dry eye condition.
HOW DO MEDICATIONS AFFECT DRY EYE?
Some medications taken for arthritis, birth control, acne, colds, allergies or other medical conditions can cause the eyes to produce fewer tears than normal. Be sure to tell your eye care specialist about all of your current medications.
HOW DO I KNOW IF I HAVE DRY EYE?
Your eye care specialist can readily determine if you have dry eye by performing a few simple tests.
WHY ARE MY EYES BETTER ON SOME DAYS THAN OTHERS?
Dry eye conditions are affected by a number of external environmental factors. Wind, heat and dry air can make dry eyes seem even worse. Wearing contact lenses can also aggravate dry eye.
IS THERE A CURE FOR DRY EYE?
There is no known cure for dry eye. However, some dry eye symptoms are caused by medications, eye infections or wearing contact lenses. In these cases, simply eliminating the cause of dry eye will stop the problem.
In many cases, however, dry eyes are a lifelong problem. You can relieve the symptoms, but not cure the original cause. Most eye care specialists recommend artificial tear products (ocular lubricants) for their patients with dry eyes. Follow your eye care specialist's recommendations in order to effectively relieve dry eye symptoms and avoid further damage to your eyes.
HOW WILL ARTIFICIAL TEARS HELP?
Artificial tears (ocular lubricants) can help relieve the symptoms of dry eye. They supplement natural tears and provide an artificial coating for the eyes.
However, some artificial tear products (those usually found in bottles) contain preservatives. Frequent use of preservatives in the eye can disrupt the integrity of natural tears and may cause dry spots on the eye. This, in turn, may make the eye more sensitive to those products.
If you are experiencing burning or stinging when using artificial tears, ask your eye care specialist to recommend a preservative-free tear product that is right for you.
TWO TYPES OF TEARS
Your eyes are lubricated by two different types of tears produced by the tear glands in your upper and lower eyelids.
Constant tears are continuously produced to lubricate the eye at all times, and contain natural antibiotics to fight infections.
Reflex tears are only produced in response to irritation, injury or emotion to help rinse the surface of the eye.
A delicate balance between constant and reflex tears, in addition to a satisfactory blink reflex, helps ensure that your eyes will be comfortable, well-lubricated and well-protected.
FIVE COMMON CAUSES OF DRY EYE SYNDROME
Blinking: Blinking helps lubricate the eye by spreading tears across its surface. As you blink, tears are forced inward to the nose, where they flow into the tear drainage ducts, and drain into the nose and throat. If the tear drainage system is overactive, dry eye symptoms or related congestion of the nose, throat or sinus may occur.
Aging: Tear production decreases with age. In fact, the volume of lubricating constant tears can be as much as 60% less at age 65 than at age 18. This reduction in constant tear flow and resulting eye irritation may cause occasional excessive reflex tearing.
Environment: High altitudes; sunny, dry, windy conditions; and the use of heaters, blowers and air conditioners increase tear evaporation and reduce eye lubrication.
Contact Lenses: Contact lens wear can dramatically increase tear evaporation, causing irritation, infection, protein deposits, and pain. Research shows that dry eye is the lending cause of contact lens discomfort.
Medications: Some medications decrease the body's ability to produce lubricating tears. These include decongestants, antihistamines, diuretics, heart disease and ulcer prescriptions, antidepressants, anesthetics and drugs containing Beta Blockers.
IMPORTANT REMINDERS FOR DRY EYE SUFFERERS
Among those who suffer from Dry Eye Syndrome and related tearing disorders, nearly half also experience related symptoms involving the nose, throat, and sinus. These include:
Nasal or sinus congestion, post nasal drip, and sneezing
Allergy and hay fever symptoms
Middle ear congestion Chronic coughing
definition & graphics courtesy of The Vision Source!
Additional keywords and misspellings:
The EyeCyclopedia™ is a collection of eye care terminology created by
practicing optometrists and ophthalmologists. The information provided is not intended
to be a substitute for regular medical care or to diagnose or treat
any medical condition, and should be used only as a supplemental source of information.
Please consult your doctor if you have any questions or concerns about your eye health.