Ophthalmology is the branch of medicine that deals with the anatomy, physiology and diseases of the eye. An ophthalmologist is a specialist in medical and surgical eye problems. Since ophthalmologists perform operations on eyes, they are both surgical and medical specialists. A multitude of diseases and conditions can be diagnosed from the eye.
Warning Signs of Eye Trouble
Blurry vision, spots, glare at night these are common eye complaints that can be harmless annoyances or an early sign of disease. Its not always easy to tell the difference. So be sure to visit an eye doctor promptly about any changes or concerns about your vision.
Color Blindness Test
Color Blindness Test
Which number do you see on the left? If it's "3," you probably have normal color vision. If it's "5," you may be color-blind. This view is simulated in the center panel and represents a mild color blindness. Complete color blindness (which is very rare) is simulated at the right. No number is visible. Tinted glasses may help color-blind peoples.
When you're near-sighted, things in the distance look blurry. Doctors call it myopia. You're more likely to have it if:
- One or both of your parents have it
- You do lots of close-up reading
Near-sightedness can make it harder to drive, play sports, or see a blackboard or TV. Symptoms include blurred vision, squinting, and fatigue. To correct it, you can wear glasses, contacts, or get surgery in some cases.
Most people are born with mild farsightedness and outgrow it in childhood. When it persists, you may see distant objects well, but books, knitting, and other close objects are a blur. This problem runs in families. Symptoms include trouble with reading, blurry vision at night, eyestrain, and headaches. To treat it, you may wear glasses or contacts. Some people get surgery for it.
Trouble reading fine print is a sign of aging. It's called presbyopia, which means "old eye" in Greek. For most people, it starts in their 40s. The eyes' lenses become less flexible and can't change shape to focus on objects at reading distance. The solution: Wear reading glasses or bifocals, which correct both near and distance vision. If you wear contacts, ask your eye doctor about contacts made for people with presbyopia.
Nearsightedness: What Happens
The cause is usually an eyeball that's too long. An abnormally shaped cornea or lens can cause it, too. Light rays focus just in front of the retina, instead of directly on it. This sensitive membrane lines the back of the eye (seen in yellow) and sends signals to the brain through the optic nerve. Near-sightedness often develops in school-age children and teens, who need to change glasses or contacts frequently as they grow. It usually stabilizes by the early 20s.
Farsightedness: What Happens
Farsightedness is often due to an eyeball that's too short. Light rays focus behind the retina, making close objects look blurry. If it's severe, distance vision can be blurred as well. An abnormal shape in the cornea or lens can also lead to farsightedness. Children with significant hyperopia are more likely to have crossed eyes (strabismus) or lazy eye (amblyopia) and may have trouble reading. That’s one of the reasons eye doctors recommend vision exams for young children.
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If you have astigmatism in one or both eyes, your vision may be out of focus at any distance. It happens when the cornea, the clear “window” that covers the front of the eye, is misshapen. Light rays can scatter to different points on the retina, rather than focus on a single point. Glasses or contact lenses correct it. Surgery may be another option. Along with blurred vision, symptoms may include headaches, fatigue, and eye strain
Do you dream of seeing clearly without glasses?
Surgery to reshape your cornea can correct near-sightedness, farsightedness, or astigmatism. It succeeds more than 90% of the time. Surgery may not be right for you if you have severe dry eye, thin or abnormally shaped corneas, or severe vision problems. Side effects can include glare or sensitivity to light.
You can't feel it, but glaucoma can steal your sight by harming your optic nerve. You may not have symptoms until you lose your central vision, after losing your peripheral vision. You need regular eye exams every 1-2 years, especially after age 40, to find it early. Doctors can treat glaucoma with medications or surgery.
Glaucoma: What Happens
In the most common form of glaucoma, increased eye pressure leads to optic nerve damage and loss of vision. Your eye is naturally filled with fluid that nourishes its internal structures. Sometimes too much fluid builds up. This buildup raises pressure and damages the optic nerve at the back, where the bundle of 1 million nerve fibers carry information to your brain. Without treatment, glaucoma can cause total blindness.The bright yellow circle shows an optic nerve head that is damaged by glaucoma. The dark central area is the macula, responsible for finely detailed central vision
Macular Degeneration: View
Age-related macular degeneration (AMD) damages and then destroys your central vision, making it hard to read or drive. Symptoms can include a central blurry spot or straight lines that appear wavy. You're more likely to have it if you are older than 60, smoke, have high blood pressure, are obese, are female, or have a family history of the condition. See your eye doctor regularly to check for AMD. Prompt treatment can help slow vision loss.
Macular Degeneration: What Happens
AMD affects the central part of the retina, called the macula. You can have "dry" or "wet" AMD. In the dry form, doctors often see yellow deposits called drusen in the macula. As it worsens, the macular tissue breaks down. That gradually hampers the delivery of images to the brain. In the wet form, abnormal blood vessels grow. They leak blood and fluid (seen here), which scars and further damages the macula. Both types leave you with a central blind spot.
Macular Degeneration: Test
Cover one eye and stare at the center dot in this Amsler grid, from a distance of 12 to 15 inches. (You can wear your reading glasses.) Do you see wavy, broken, or blurry lines? Are any areas distorted or missing? Repeat for your other eye. Although no self-test can substitute for an eye exam, this grid can help detect early symptoms of AMD.
Next: See how this grid looks with AMD.
Macular Degeneration: Signs
As seen here, the Amsler grid can look quite distorted to someone with significant macular degeneration and may include a central dark spot. Straight lines that appear wavy are also cause for concern, as they can be an early symptom of "wet" AMD, the more serious and fast-moving type of macular degeneration. See your eye doctor right away for a dilated eye exam.
Diabetic Retinopathy: View
Type 1 and type 2 diabetes can cause partial vision loss (seen here) and lead to blindness. The damage involves tiny blood vessels in the retina. It can often be treated, but don't wait for symptoms. By the time they happen -- blurry vision, spots, shadows, or pain -- the disease may be severe. People with diabetes need annual eye exams, sometimes even more often if they already have diabetic eye changes. The best prevention is to keep your blood sugar in check.
Diabetic Retinopathy: What Happens
High blood sugar levels can damage the tiny blood vessels that support the retina. These blood vessels can swell, break, and leak fluid. In some cases, dozens of new, abnormal blood vessels grow, a condition called proliferative retinopathy. The abnormal vessels are very fragile and break open easily. These processes gradually damage the retina, causing blurred vision, blind spots, or blindness.
By age 80, more than half of us will have had a cataract, or clouding of the lens. Vision gradually gets foggy and makes it hard to read, drive, and see at night. Diabetes, smoking, or too much time in the sun raise that risk. Surgery that replaces the clouded lens with an artificial lens is highly effective.
Cataracts: What Happens
A healthy lens focuses light into a sharp, clear image on the retina, which captures the image like film in a camera. As we age, protein builds up in the lens, clouding it. That scatters rays of light on the retina, instead of focusing it for one sharp, clear image. The result can be blurred vision, changes in color vision, and glare, especially at night. Very advanced cataracts are noticeable, such as the muddy-colored circle at the centre of this picture.
Retinitis Pigmentosa (RP)
You can inherit this disorder from your parents. It often begins with night vision problems. Next comes a gradual loss of side vision, which develops into tunnel vision, and finally, in some cases, blindness. One study showed that high-dose vitamin A supplements can curb vision loss. But you should see a doctor before taking supplements because too much vitamin A can be toxic.
Retinitis Pigmentosa: What Happens
In people with RP, the light-sensitive tissue of the retina slowly dies over many years. As that happens, the tissue stops sending signals to the brain, and you lose some vision. Eye exams show abnormal dark spots (pigments) sprinkled around the retina. Early cataracts can also happen, as well as a swelling of the retina, called macular edema (the central orange mass seen here).
Floaters and Specks
Blurry spots or specks in your vision that move may be floaters, which are debris in the eye's vitreous gel. They don't block vision and are easier to see in bright light. Floaters are common and usually harmless. But if they appear or increase suddenly, or you also have light flashes, see a doctor. Persistent white or black spots and a sudden shadow or loss of peripheral vision need immediate medical attention.
Amblyopia (Lazy Eye)
As a child, if one of your eyes can't see well, your brain sometimes favors your other eye. This condition, called amblyopia, may happen because of an alignment problem of the eyes (strabismus or crossed eyes) or poorer vision in one eye. A patch or drops that blur the vision in the "good" eye can prod the brain to use the other eye. If it's not treated during childhood, vision loss from amblyopia can be permanent.
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Eye Care: Object in the Eye
Many nerve endings are just beneath the surface or your cornea, so a tiny speck can be painful. Don't rub the eye, or you may cause serious damage. Gently flush the eye with lukewarm water. If that doesn't dislodge the object, call a doctor who can remove it and give you antibiotic drops to protect your cornea from infection.
Tears and Dry Eye
Tears lubricate your eyes. When not enough flow, perhaps due to dry air, aging, or other health conditions, your eyes can become painful and irritated. For people with mild cases of dry eye, occasionally using eyedrops labeled artificial tears may do the trick. If it's a bigger problem, you may need other medications or a procedure to fix it.
This eye problem is inflammation caused by a virus, bacteria, irritant, or allergy. Your eye is red and you might feel itching or burning and have a discharge from that eye, too. If itching is your main symptom, an allergy is a likely cause. Most cases of infectious pinkeye are viral, which don't need antibiotics. Your doctor will only give you antibiotic eyedrops if your pinkeye is due to bacteria. Both bacterial and viral conjunctivitis are very contagious, so wash your hands often while you wait for it to clear up.
A stye is a tender, red bump that looks like a pimple on or near the edge of the eyelid. It is one type of infection of the eyelids (blepharitis). Styes usually heal in a week. You can use a very warm, wet compress three to six times a day to speed up the recovery. Don’t wear contact lenses or eye makeup until it's healed
Allergies can give you watery, itchy eyes. Pollen, grass, dust, weeds, and pet dander are common triggers. An allergy doctor can tell you what to avoid. Keep your windows shut at home and in your car. Use special mattress and pillow covers that keep allergens out. Clean your house thoroughly, and use allergen filters in your furnace and air conditioner. Allergy eyedrops, artificial tears, and antihistamines also may help.
Keep Up With Your Eye Exams
You need regular eye exams all through your life, especially if eye problems run in your family or if you have other risk factors. An eye exam can also find other conditions, such as diabetes and high blood pressure, or even a stroke or brain tumor. Bulging eyes are a sign of thyroid disease, and a yellow tint of the whites of the eyes can be a sign of liver problems.
Eye Protection: Sun
UV rays can harm your eyes. Over time, getting too much sun can cause cataracts 8-10 years early. Just one long session in the sun can burn your corneas. So wear a hat and sunglasses that block UV rays. You can also add a protective, clear UV blocking film to your car’s side windows. People with light-colored eyes tend to be more sensitive to light. If you're suddenly more sensitive to light than usual, see your eye doctor, since that can be a sign of an eye problem.
Protect Your Eyes
Grease splatters from a pan, yard debris flies up from the lawn mower, cleaning solution splashes in a bucket. Some of the greatest hazards to your eyes are in your home. Eye care specialists recommend that every household have ANSI-approved protective eyewear. Even if an eye injury seems minor, go to the emergency room right away to check it out.
Foods for Eye Health
Carrots really are good for your eyes. So are spinach, nuts, oranges, beef, fish, whole grains, and many other foods in a healthy diet. Look for foods with antioxidants such as omega-3 fatty acids; vitamins C, E, and beta-carotene; as well as zinc, lutein, and zeaxanthin. Research shows those nutrients may make age-related macular degeneration less likely.