The eye: for kids
What part of your body lets you read the back of a cereal box, check out a rainbow, and see a softball heading your way? What part lets you cry and makes tears to protect itself? What part has muscles that adjust to let you focus on things that are close up or far away? If you guessed the eye, you're right!
Your eyes are at work from the moment you wake up to the moment you close them to go to sleep. They take in tons of information about the world around you - shapes, colors, movements, and more. Then they process the information and send it to your brain so it knows what's going on outside of your body.
You can see that the eye's pretty amazing. So come on - let's take a tour of its many parts.
Eye See
You can check out different parts of the eye by looking at your own eye in the mirror or by looking at (but not touching) a friend's eye. Some of the eye's parts are easy to see, so most friends will say OK. Most friends will not say OK if you ask to see their liver!
The eye is about 1 inch (25 millimeters) wide, and it sits in a little hollow area (the eye socket) in the skull, where it's protected by the eyelid. The eyelid helps keep the eye clean by opening and shutting several times a minute. This is called blinking, and it's an involuntary action, which means you don't control it.
The eyelid also has great reflexes that protect the eye. When you step into bright light, for example, the eyelids squeeze together tightly to protect your eyes, until they can adjust to the light. And if you flutter your fingers close (but not too close) to your friend's eyes, you'll be sure to see the eyes blink. Your friend's eyelids shut automatically to protect the eye from possible danger. And speaking of fluttering, don't forget eyelashes. They work with the eyelids to keep dirt and other unwanted stuff out of your eyes.
The white part of the eyeball is called the sclera (say: sklair-uh). The sclera is made of a tough material and has the important job of covering most of the eyeball. Look very closely at the white of the eye, and you'll see lines that look like tiny pink threads. These are blood vessels that bring blood to the eye.
The next layer on the eye is the cornea (say: cor-nee-uh), which helps the eye focus. It is a very important part of the eye, but you can hardly see it because it's made of clear tissue.
Behind the cornea are the iris and the pupil. The iris (say: eye-riss) is the colorful part of the eye. When we say a person has blue eyes, we really mean the person has blue irises! The iris has muscles that adjust to control how much light goes through the pupil (say: pyoo-pul). The pupil is the black circle in the center of the iris, and it lets light enter the eye. To see how this works, use a small flashlight to see how your eyes, or a friend's eyes, respond to changes in brightness. The pupils will get smaller when the light shines near them and they'll open wider when the light is gone.
Between the iris and cornea is the anterior (say: an-teer-ee-or) chamber. This chamber is filled with a special fluid that gives the eye oxygen, protein, and glucose (a type of sugar in the body) to keep it healthy.
Light, Lens, Action
These next parts are really cool, but you can't see them with just your own eyes! Doctors use special magnifying scopes to look at these inner parts of the eye, such as the lens. After light enters the pupil, it hits the lens. The lens sits behind the iris and is clear and colorless. The lens' job is to focus light rays on the back of the eyeball - a part called the retina (say: reh-tin-uh).
The lens is suspended in the eye by a bunch of fibers. These fibers are attached to a muscle called the ciliary (say: sih-lee-air-ee) muscle. The ciliary muscle has the amazing job of changing the shape of the lens. That's right - the lens actually changes shape right inside your eye! Try looking away from your computer and focusing on something way across the room. Even though you didn't feel a thing, the shape of your lenses changed. When you look at things up close, the lens becomes thicker to focus the correct image onto the retina. When you look at things far away, the lens becomes thinner.
The biggest part of the eye sits behind the lens and is called the vitreous (say: vih-tree-us) body. It's filled with a clear, goopy material called the vitreous humor. Ever touch toy eyeballs in a store? Sometimes they're kind of sticky or squishy - that's because they're made to feel like they're filled with vitreous humor. In a real eye, after light passes through the lens, it shines straight through the vitreous humor to the back of the eye.
Your retina is in the back of the eye, past the vitreous body. The retina is smaller than a dime, but it holds millions of cells that are sensitive to light. The retina takes the light the eye receives and changes it into nerve signals so the brain can understand what the eye is seeing.
Rods and Cones
The retina uses special cells called rods and cones to process light. Just how many rods and cones does your retina need? How about 120 million rods and 7 million cones - in each eye!
Rods see in black, white, and shades of grey and tell us the form or shape that something has. Rods can't tell the difference between colors, but allow us to see when it's dark.
Cones sense color and they need more light than rods to work well. Cones are most helpful in the light. The retina has three types of cones - red, green, and blue - to help you see different ranges of color. Together, these cones can sense combinations of light waves that enable our eyes to see millions of colors.
Rods and cones process the light to give you the total picture. You're able to see that your friend has brown skin and is wearing a blue hat while he tosses an orange basketball.
Sometimes someone's eyeball changes shape and the cornea, lens, and retina no longer work perfectly as a team. The person's eye may focus on what it sees in front of or behind the retina, instead of on the retina. When this happens, most of what the person sees will be out of focus.
To correct this fuzzy vision, many people, including some kids, wear glasses. Glasses help the eyes focus images correctly on the retina and allow someone to see clearly. As adults get older, their eyes change shape and they often need glasses to see things up close. Most older people you know - like your grandparents - probably put on reading glasses to look at the newspaper or a menu at a restaurant.
To the Brain!
Think of the optic nerve as a great messenger in the back of your eye. The rods and cones change the colors and shapes you see into nerve messages. Then, the optic nerve carries those messages from the retina to the brain!
Here's something interesting: when light passes through the eye's lens and the image hits the retina, the image is upside down. So the message that the optic nerve brings to the brain is upside down, too! An upside-down message doesn't make any sense to your brain. Imagine trying to figure out how to shoot a basket in an upside-down gym! But luckily, your brain knows how to flip the image over so it's right-side up. Now it can understand what you're seeing and make decisions about what to do, like take that 3-point shot at the basket! Whoosh!
Have No Fear, You Have Tears
For crying out loud, the eye has its own special cleaning system - tears! Above the outer corner of each eye are the lacrimal (say: lah-krim-ul) glands, which make tears. Every time you blink your eye, a tiny bit of tear fluid comes out of your upper eyelid. It washes away germs, dust, or other particles that don't belong in your eye. It also keeps your eye from drying out. Then the fluid drains out of your eye by going into the lacrimal duct (this is also called the tear duct). You can see the opening of your tear duct if you very gently pull down the inside corner of your eye. When you see a tiny little hole, you've found the tear duct.
Your eyes will make more tear fluid than normal to protect themselves. This may have happened to you if you've been poked in the eye, if you've been in a dusty or smoking area, or if you've been near someone who's cutting onions.
And how about the last time you felt sad, scared, or upset? Your eyes got a message from your brain to make you cry, and the lacrimal glands made many, many tears.
Your eyes do some great things for you, so take these steps to protect them:
Wear goggles in classes, where debris or chemicals could go flying, such as wood shop, metal shop, science lab, or art.
Wear eye protection when playing racquetball, hockey, skiing, or other sports that could injure your eyes.
Wear sunglasses. Too much light can damage your eyes and cause vision problems, such as cataracts, later in life.
The eyes you've got will be yours forever - treat them right and they'll never be out of sight!
Reviewed by: Kim Rutherford, MD
Date reviewed: December 2002
Originally reviewed by: Jane Edmond, MD
Drugs Restoring Eyesight in Seniors
Source: American Diabetes Association
Publication date: 2002-07-02
2002-07-01
By DANIEL Q. HANEY
AP Medical Editor
BOSTON (AP) _ To doctors' amazement, experimental new medicines are rescuing people from the brink of blindness so they can read and drive and sometimes even regain perfect vision.
These lucky few are the first beneficiaries of an entirely new category of drugs that many hope will revolutionize the care of common eye diseases.
Several competing medicines are in development, all based on similar principles. They are designed to stop the two top causes of adult blindness _ the "wet" form of macular degeneration, which affects the elderly, and diabetic retinopathy, the biggest source of blindness in working-age people.
Vision loss seems halted for most if they take the drugs soon after their symptoms begin. Some experience stunning reversals of what would have been inevitable blindness.
"I'm telling you, it's miraculous," says Eileen Russell.
Russell, 76, of Worcester, lost vision in her right eye four years ago. In May, her left eye went bad, too, and she was declared legally blind.
But after four injections of one of the drugs her left eye is 20-25. She drives and reads and is thinking about returning to work as a nurse.
"Yesterday, I had to write a check," she says. "It looked beautiful, right on the line, with a regular pen. I can do all the little things again."
Around the country, about 70 patients with wet macular degeneration have been treated with the same drug as Russell, Genentech's rhuFab. About half were treated by Dr. Jeffrey Heier of Ophthalmic Consultants of Boston, who says, "I can honestly say I have never seen anything as exciting as this."
Experts caution that most of the results from the studies on this and similar drugs will not be known for at least a year or two. And for now, the treatments are available only to study volunteers.
None of the drugs are intended for the more common but less aggressive "dry" kind of macular degeneration, nor will they work after eyesight has been gone for months.
Guessing the drugs' ultimate effectiveness based on early testing is risky. Still, doctors estimate that roughly one-quarter to one-third of people with newly diagnosed wet macular degeneration have had significant improvement in their eyesight. In most of the rest, loss of sight is stopped, at least temporarily.
Among others helped by rhuFab is Ernest Hayeck, a retired judge in Worcester, 40 miles west of Boston. One day last September, he discovered he was quickly going blind in his right eye. Doorways looked wavy, and everything was dim.
Doctors said they could do nothing for him. With wet macular degeneration, vision in that eye would cloud to little or nothing within a few months at best.
Hayeck was an active retiree, nine years off the state Superior Court but busy on the faculty of the National Judicial College and the board of Wendy's International.
"I was resigned to it," he remembers. "I told myself I had had 77 good years."
But when told of Heier's rhuFab study, he seized the chance, even though it meant getting shots in his bad eye. In October, the judge got his first, which he said was painless. By then his sight had failed to 20-100.
"I have achieved what I consider to be a miraculous result," says Hayeck. "My eyesight came back with a vengeance. By the time I had the fourth treatment, I was 20-20 with my glasses on."
Another of Heier's patients, Edward Nowak, 81, an outdoor writer and photographer in suburban Needham, found vision in his left eye improved from 20-400 last November to 20-50 now.
"The results have been miraculous," he says. "You would think the good Lord himself did this."
Dr. Steven Schwartz, chief of the retina division at UCLA's Jules Stein Eye Institute, has worked with several of the new drugs. "For the first time in my career, I have actually been able to restore vision in patients who otherwise would never be able to get back their central vision," he says. "It is a spectacular advance."
His macular degeneration patients include the actor Dabney Coleman, who in a week on rhuFab went from 20-400 to 20-40 in his left eye and returned to playing tennis.
An estimated 200,000 new cases of wet macular degeneration are diagnosed in the United States annually. About 4 million U.S. diabetics have some degree of retinopathy, and 24,000 go blind each year.
Both diseases result from misguided growth of blood vessels in the eyes. Since the new drugs attack this underlying problem, doctors hope they will work for both diseases.
The need for new treatments is expecially dire in wet macular degeneration, because nothing can be done for most victims. Blindness often follows within months or even weeks of the first symptoms.
It occurs when leaky blood vessels sprout behind the retina, probably in a mistaken attempt to fix the slow breakdown of light-sensitive cells that occurs with age. These vessels ooze fluid and damage the fragile tissue that controls straight-ahead vision.
The new drugs vary, although most of them, like rhuFab, zero in on a growth-promoting protein called vascular epidermal growth factor, or VEGF. It appears to be an especially important trigger of damaging blood vessels in both forms of blindness.
Other drugs in testing include:
--Anecortave acetate from Alcon, a new steroid injected next to the eye once every six months for macular degeneration.
--Eyetech Pharmaceuticals' EYE001, which is injected into the eyeball like rhuFab for macular degeneration.
--Bausch & Lomb's Retisert implant, which exudes a steroid into the eye for up to three years and is being used for diabetic retinopathy and macular degeneration.
--Lilly's LY333531, the only pill among the new drugs; used to prevent worsening eye disease in diabetics.
Development of these drugs is gratifying to Dr. Judah Folkman of Boston's Children's Hospital, whose three decades of pioneering research into blood vessels provided their scientific basis. Folkman's goal is a cancer treatment, since new blood vessels are necessary for tumor growth.
"Sometimes the most exciting thing in a scientist's career," he says, "is an unexpected outcome from one's work."
Nevertheless, experts caution that until the big studies are finished, no one can be sure how well the drugs will work. No one knows how long patients will need to take them, how often disease will return or whether the repeated eye injections have any hazards.
"The early data are very exciting, but it would be premature to extrapolate to cures or use other such adjectives to describe these isolated but impressive vision recoveries," says Dr. Karl Csaky of the National Eye Institute.
"Even if these drugs are as successful as the stockholders' wildest dreams, we'll still need something better," adds Dr. David Weissgold of the University of Vermont, "because they won't make the problems go away."
For elderly victims of macular degeneration, though, even a temporary reprieve from blindness is welcome.
"I'm reconciled to the possibility this is a gift that won't last forever," says Hayeck. "I may lose it again. But I can't complain. I've gotten a good year out of this."
EDITOR'S NOTE: Medical Editor Daniel Q. Haney is a special correspondent for The Associated Press.
Publication date: 2002-07-02
© 2002, YellowBrix, Inc.
Guidelines on Who Should Get Laser Eye Surgery
NEW YORK (Reuters Health) - Laser eye surgery can help clear up blurry vision, but new guidelines on the procedure emphasize that not every spectacled person is a candidate.
LASIK eye surgery is often successful in improving the common vision problems of near-sightedness, far-sightedness and astigmatism. But before going under the laser, patients should be screened for problems that make them non-candidates and should have realistic expectations about their post-surgery vision, according to guidelines issued by the American Society of Cataract and Refractive Surgery (ASCRS).
LASIK (for laser assisted in situ keratomileusis) is performed about 1.5 million times a year in the US. The procedure corrects vision problems by reshaping the cornea, the clear covering over the front of the eye.
While it is generally safe and major complications leading to vision loss are rare, LASIK is not for everyone, according to the ASCRS.
For example, "non-LASIK candidates" include people with eye diseases like cataracts, advanced glaucoma and disorders marked by thinning of the cornea. A measurement of the eyes' corneal thickness is among the examinations that should be done before LASIK surgery, according to the new guidelines. Other steps include measuring pupil size, examining the cornea for abnormalities and measuring the ability of the muscles to align the eyes.
The guidelines also cite factors that make a patient a "less-than-ideal" candidate for LASIK. People who have immune system disorders or are taking drugs that suppress the immune system fall into this category, as post-surgery healing may be hindered. Patients with a history of dry eyes are also not ideal candidates because this problem can worsen after LASIK.
Besides dry eyes, other potential side effects of LASIK include seeing "starbursts" and "halos" and having trouble driving at night.
According to the ASCRS guidelines, patients should be fully informed of these side effects before surgery and should have realistic expectations about their post-LASIK vision.
"LASIK cannot provide perfect vision every time for every patient," notes the committee that developed the guidelines. In addition, repeat procedures may be necessary, and even then, a person's vision may not be as good as it was with corrective lenses.
age-related macular degeneration (AMD)
Is your vision becoming wavy, spotty, or distorted? These changes may not be just part of getting older. You may have age-related macular degeneration (AMD) or other abnormalities of the eye.
AMD is typically a progressive eye condition that destroys light-sensitive cells in your eyes. When these cells are damaged, there can be a loss of fine detail vision.
AMD does not destroy all of your vision. Your side, or "peripheral," vision will not be affected, so you can rely on it more to help you see. This means your vision will not go totally black. You will still be able to see shapes, light, and movement; however, AMD blurs the sharp vision needed for straight-ahead activities such as reading, sewing, and driving.
AMD can lead to central vision loss in people 50 years old or above. If you are one of approximately 15 million Americans who has AMD, there are actions you can take to help save your sight.
Treating AMD
Currently, there is no cure for macular degeneration. Treatment, however, may prevent some vision loss and slow progression of the condition. Several options are available, including:
Treatments for Dry AMD
Dietary supplements: Dietary supplements such as vitamins C, E, beta-carotene, and zinc have been shown to decrease the risk of vision loss in patients with intermediate to advanced dry AMD. The Age-Related Eye Disease Study (AREDS) showed that people with the intermediate stage of dry AMD could reduce their risk of progressing to advanced AMD by about 25% by taking a special high-dose formula of the supplements, sold without a prescription. It is important to note that high-dose vitamins, even when sold without a prescription, may present a risk for some people. Smokers taking beta-carotene may increase their risk of lung cancer. We strongly encourage you to talk to your doctor about the risks and benefits of these dietary supplements before taking them.
Current Treatments for Wet AMD
Laser therapy: High-energy laser light is used to destroy actively growing abnormal blood vessels that occur in macular degeneration.
Photodynamic laser therapy: A two-step treatment in which a light-sensitive drug is used to close the abnormal blood vessels. Your doctor injects the drug into your arm or hand vein. It is absorbed by abnormal blood vessels in your eye. Your doctor then shines a cold laser light into your eye, to activate the drug, helping to close the abnormal blood vessels. This therapy usually requires multiple treatments. Currently, this treatment is approved by the FDA for approximately 25% of wet AMD patients.
Investigational Treatments for Wet AMD
Anti-VEGF Therapy: New research is under way to try to block retinal blood vessel growth and stop the leakage from these vessels, which is believed to lead to wet AMD disease.
Pinkeye (Conjunctivitis)
What Is It?
Conjunctivitis, also called pinkeye, is an inflammation of the conjunctiva, the transparent membrane which lines the eyelids and covers the whites of the eyes. Conjunctivitis can be triggered by allergies, by contact with irritating chemicals, or by infections. When conjunctivitis is due to infections, the cause may be either viral or bacterial:
Viral conjunctivitis — Viral conjunctivitis often is caused by one of the adenoviruses, a family of viruses that typically produces upper-respiratory illnesses (colds). In temperate climates, adenoviruses are most common during the spring, early summer and mid-winter. Adenoviruses can be found in fluids from the eyes, mouth, and nose of infected patients, and they can spread from person to person on hands and in the droplets of coughs and sneezes. In most cases, adenoviruses produce only a simple superficial conjunctivitis; however, they also are capable of producing keratoconjunctivitis, a more serious infection that can cloud the cornea and interfere with normal vision. Besides adenoviruses, other viral causes of conjunctivitis include enteroviruses, the measles virus (rubeola), and the herpes simplex virus.
Bacterial conjunctivitis — Bacterial conjunctivitis can be caused by several different types of bacteria, including: Haemophilus influenzae, pneumococci, staphylococci (staph) and streptococci (strep). As with viral conjunctivitis, most of these bacterial infections are spread through contact with hands that carry the bacteria. Children born to mothers with vaginal gonorrhea or chlamydia infections also can develop gonorrheal or chlamydial conjunctivitis if their eyes are infected by contaminated secretions in the birth canal during vaginal delivery.
Symptoms
Symptoms of conjunctivitis include red, watery eyes; eye discomfort that feels "itchy" or "scratchy;" and an eye discharge that may form crusts around the eyelashes. In viral conjunctivitis, this eye discharge tends to be thin, clear, and watery, while in bacterial conjunctivitis it is often thick, discolored (yellow or greenish), cloudy and sticky.
Sometimes the discharge is so sticky that the eyelids actually may adhere to one another. This is most likely to happen after sleeping, especially when the patient awakens in the morning. With allergic conjunctivitis, both eyes usually are involved, itching is more intense, and swelling of the eyelids may occur.
If you are a contact-lens wearer, you have a higher risk for developing severe conjunctivitis that can damage the eye. Stop wearing contact lenses if you develop a red eye. Contact a health professional immediately if there is any pain.
Diagnosis
A diagnosis of conjunctivitis is suspected when a person develops an itchy, red eye with a discharge or increased tearing. The presence of pain may indicate that more than conjunctivitis is causing the red eye. If your doctor suspects bacterial conjunctivitis, he or she may take a swab of your eye discharge to be cultured (checked for bacterial growth) in the laboratory.
Expected Duration
Even without treatment, most cases of viral conjunctivitis resolve within seven days.
Bacterial conjunctivitis should be treated with an antibiotic. When this is done, the eye redness of bacterial conjunctivitis usually begins to clear up within a couple of days.
Prevention
It is possible to prevent infectious conjunctivitis. Wash your hands frequently and avoid touching your eyes. At home, never share towels, wash cloths or facial cosmetics with others, especially eye makeup.
Since untreated gonorrhea and/or chlamydia eye infections can damage the eyes of newborn babies, all pregnant women should be tested and, if necessary, treated for gonorrhea and/or chlamydia vaginal infections. As another preventive measure, newborns routinely are treated at birth with antibiotic eye drops.
Treatment
Most patients with uncomplicated viral or bacterial conjunctivitis are treated with either prescription or nonprescription eye medication. For uncomplicated viral conjunctivitis, you doctor may suggest a specific type of nonprescription eyedrops. You can use these to relieve eye symptoms while your body fights off the viral infection. For bacterial conjunctivitis, prescription ointment or eyedrops containing antibiotics (sulfacetamide, erythromycin, or others) are necessary. You must use these for as many days as your doctor directs, even though symptoms may clear within a day or two.
For bacterial conjunctivitis, you also can try applying warm compresses to your eyes for 20- to 30-minute periods, several times a day. Gently wipe away eye discharge and crusts with a clean, moist cotton ball or tissue. For allergic conjunctivitis, antihistamine eyedrops and cool compresses can help relieve itching.
Newborns who develop gonorrheal or chlamydial conjunctivitis after birth must be treated with intravenous antibiotics. Their mothers also should be examined and treated for gonorrhea or chlamydia infections.
When To Call A Professional
Call your doctor if your eyes become red, watery, and itchy, especially if there is a thick eye discharge that crusts on your eyelids. Call your doctor immediately if you have pain and/or swelling in your eyes, or if you develop blurred vision, a high fever or light sensitivity. Also call your doctor immediately whenever an infant, especially a newborn, shows symptoms of conjunctivitis.
If you are being treated for bacterial conjunctivitis, check with your doctor if your eye redness persists after three days of antibiotic therapy.
Prognosis
Most cases of uncomplicated viral or bacterial conjunctivitis resolve without causing permanent eye damage.
Additional Info
National Eye Institute
2020 Vision Place
Bethesda, MD 20892-3655
http://www.nei.nih.gov/
American Academy of Ophthalmology
P.O. Box 7424
San Francisco, CA 94120
Phone: (415) 561-8500 begin_of_the_skype_highlighting (415) 561-8500 end_of_the_skype_highlighting
http://www.aao.org/
Last updated May 28, 2001
Facts about Eye Allergies
Believe your eyes, and see what they may be telling you.
If your eyes itch, are red, tearing or burning, pay attention to what they may be telling you. You may have eye allergies, or allergic conjunctivitis, a condition that affects millions of Americans. It is a condition that can occur alone, but often accompanies nasal allergy symptoms, such as sneezing, sniffling and a stuffy nose. And, while most people treat nasal allergy symptoms, they often ignore their itchy, red, watery eyes. This document answers questions about eye allergies and suggests effective ways for you to recognize and treat the symptoms.
What causes eye allergies?
Just like hay fever and skin rashes, eye allergies develop when the body's immune system becomes sensitized and overreacts to something that is ordinarily harmless. An allergic reaction can occur whenever that "something" - called an allergen - comes into contact with your eyes. The allergen causes certain cells in the eye (called mast cells) to release histamine and other substances or chemicals that cause blood vessels in the eyes to swell, and the eyes to become itchy, red and watery.
What allergens trigger eye allergies?
Allergens that may be present indoors or outdoors can cause eye allergies. The most common outdoor airborne allergens are grass, tree and weed pollens. People who are sensitive to these allergens suffer from seasonal allergic conjunctivitis, the most common type of eye allergy.
Pet hair or dander, dust mites and molds are the most common indoor allergens. These indoor allergens can trigger symptoms for some people throughout the year, resulting in perennial allergic conjunctivitis.
Although cigarette smoke, perfume and diesel exhaust may inflame your eyes, they act as irritants rather than triggering an allergic response. They can, however, make your allergy symptoms worse.
Can eye allergies harm my eyesight?
No. Eye allergies can be extremely annoying and uncomfortable, and they may disrupt your day-to-day activities, but they cannot harm your eyes.
How are eye allergies treated?
As with any allergy, the first approach for successful management should be prevention or avoidance of the allergens that trigger your symptoms. Here are some avoidance tips to reduce exposure to allergens that affect your eyes.
Stay indoors as much as possible when pollen counts are at their peak, usually during the mid-morning and early evening, and when wind is blowing pollens around.
Keep windows closed and use air conditioning in your car and home. Air conditioning units should be kept clean. Avoid using window fans that can draw pollens and molds into the house.
Wear glasses or sunglasses when outdoors to minimize pollen getting into your eyes.
Avoid rubbing eyes, which will only irritate them or make your condition worse.
Reduce dust mite exposure in your home, especially the bedroom. Bedding, particularly pillows, should be encased in "mite-proof" covers. Wash bedding often in hot water (at least 130*F). Keep humidity in your home low (between 30 percent and 50 percent).
Clean floors with a damp rag or mop rather than dry dusting or sweeping.
Wash your hands immediately after petting any animals. Remove and wash clothing after visiting friends with pets.
If you have a pet to which you are allergic, keep it out of your house as much as possible. If the pet must be in the house, keep it out of the bedroom so you are not exposed to animal allergens while you sleep. Close the air ducts to your bedroom if you have forced-air or central heating/cooling. Replace carpeting with hardwood, tile or linoleum which are easier to keep dander free.
Reduce indoor molds caused by high humidity by cleaning bathrooms, kitchens and basements regularly. A dehumidifier can be used to reduce molds, especially in damp, humid places like basements. Make sure the dehumidifier is cleaned often. To clean moldy areas in the home, use a 1-to-10 parts diluted mixture of chlorine bleach and water.
Because many of the allergens that trigger eye allergies are airborne, avoidance is not always possible. You should discuss your eye allergy symptoms with an allergy specialist or your personal physician to determine which of several treatment options is right for you. On the next two pages is a list of the kinds of over-the-counter (OTC) and prescription eye drops and oral medications that are available for the treatment of eye allergies.
Are the OTC and prescription eye drops and medications safe for children?
There are eye drops and oral medications available to treat eye allergies in children. Artificial tears are extremely safe and can be used at any age. Some eye drops, such as antihistamines and antihistamines/mast cell stabilizers, can be used in children who are 3 and older. Any treatment should be discussed with your child's physician.
Do allergy shots treat eye allergies?
If avoidance, oral medication and eye drops do not control your symptoms, allergy shots or immunotherapy is another option for relieving eye allergies. Tiny amounts of the allergen are injected with gradually increasing doses over time. The shots can actually keep your body from reacting to the allergens. The treatment takes several months to achieve maximum results and some continuing medication may still be required.
Medications for the Treatment of Eye Allergies
Over-the-counter eye drops and oral medications are commonly used for short-term relief of some eye allergy symptoms. However, they may not relieve all symptoms, and prolonged use of some OTC eye drops may actually cause your condition to become worse.
Prescription eye drops and oral medications also are used to treat eye allergies. Prescription eye drops provide both short- and long-term targeted relief of eye allergy symptoms, and they can be used to manage eye allergy symptoms in conjunction with an oral antihistamine that might be taken to manage nasal allergy symptoms.
OTC Eye Drops and Medications
Tear Substitutes. Artificial tears can temporarily wash allergens from the eye and also moisten the eyes, which often become dry when red and irritated. These drops, which can be refrigerated to provide additional soothing and comfort, are safe and can be used as often as necessary.
Decongestants-Antihistamines. Decongestants or vasoconstrictors are available as over-the-counter eye drops to reduce the redness associated with eye allergies. (Eye drops containing vasoconstrictors should not be used by anyone with glaucoma.) The decongestant drops are available alone or in conjunction with an antihistamine, which provides additional relief of itching. The drops are weak and must be used frequently (four to six times a day). It is very important not to use these OTC eye drops for more than two to three days. Prolonged use can actually lead to increased swelling and redness that may last even after discontinuing the drops. You may be familiar with this "rebound effect" that occurs when you use decongestant nasal sprays for more than three days, and your nose becomes even more congested than before.
Oral Antihistamines. Oral antihistamines can be mildly effective in relieving the itching associated with eye allergies, however these medications may cause dry eyes and potentially worsen eye allergy symptoms. Also, some OTC versions of these medications can cause side effects such as sedation, excitability, dizziness or disturbed coordination.
Prescription Eye Drops and Medications
Antihistamines. Eye drops that contain antihistamines can reduce the itching, redness and swelling associated with eye allergies. Although antihistamine eye drops provide quick relief, the effect may last only a few hours, and some of these drops need to be used four times a day.
Mast Cell Stabilizers. Mast cell stabilizers are eye drops that prevent the release of histamine and other substances that cause allergy symptoms. The drops must be taken before exposure to an allergen to prevent itching.
Antihistamine/Mast Cell Stabilizers. Some of the newest eye drops have both an antihistamine and a mast cell stabilizing action to treat and prevent eye allergies. They are used twice a day and provide quick and long-lasting relief of itching, redness, tearing and burning.
NSAIDS. Nonsteroidal anti-inflammatory eye drops also are available to relieve itching. These drops may cause stinging or burning when applied and may need to be used four times a day.
Corticosteroids. Steroid eye drops can help treat chronic and severe eye allergy symptoms such as itching, redness and swelling, but continued use of the drops can have side effects, such as a risk of secondary infection, glaucoma and cataracts. These drops should only be used short-term and under the supervision of an ophthalmologist.
Nonsedating Oral Antihistamines. Like OTC oral antihistamines, prescription antihistamines can be mildly effective in relieving the itching associated with eye allergies. They do not have the same sedating side effects as OTC antihistamines, but they still can cause dry eyes and worsen symptoms.
Your allergist or personal physician can help determine which treatments are best for you.
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The American College of Allergy, Asthma & Immunology
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Posted February 21, 2002
