Eye & Ear Doctors are experts in medical diagnosis and treatment of all diseases and conditions of the eye. The following resources provide detailed information on some of the more common eye conditions:
What are refractive errors?
Refractive errors include myopia, hyperopia, presbyopia, and astigmatism, eye conditions that are very common. Most people have one or more of them. Refractive errors can usually be corrected with eyeglasses or contact lens.
What is myopia (nearsightedness)?
If you have myopia you can clearly see close objects, but distant objects are blurry. Myopia is caused by the eyeball being too long. Myopia occurs in different degrees from minimal to extreme. The more myopic you are the blurrier your vision is at a distance and objects will have to be closer to you so you can see them clearly.
What is hyperopia (farsightedness)?
If you have hyperopia, you can see distant objects clearly, but close ones are blurry. Hyperopia occurs when the eyeball is too short for the light rays to focus clearly on the retina.
What is astigmatism?
If you have an astigmatism, the surface of the eye (cornea) is not perfectly round, rather it is more oval and doesn’t allow the eye to focus clearly. The cornea is very important in helping the eye focus light rays on the retina. Astigmatism rarely occurs alone. It is usually accompanies myopia or hyperopia.
What is presbyopia?
If you have presbyopia, you have the loss of the ability to focus up close that occurs as you age. Most people are between 40 and 50 years when they realize for the first time that they can’t read objects close to them. The letters of the phonebook are “too small” or you have to hold the newspaper father away from your eye to see it clearly. At the same time your ability to focus on objects that are far way remains normal.
What is glaucoma?
Glaucoma is an eye disease in which the normal fluid pressure inside the eyes slowly rises, leading to vision loss–or even blindness. This brochure is about open-angle glaucoma, the most common form of the disease.
What causes it?
At the front of the eye, there is a small space called the anterior chamber. Clear fluid flows in and out of the chamber to bathe and nourish nearby tissues. In glaucoma, for still unknown reasons, the fluid drains too slowly out of the eye. As the fluid builds up, the pressure inside the eye rises. Unless this pressure is controlled, it may cause damage to the optic nerve and other parts of the eye and loss of vision.
Who is most likely to get it?
Glaucoma is a leading cause of blindness in the United States. Although anyone can get glaucoma, some people are at higher risk. They include:
- Blacks over age 40.
- Everyone over age 60, especially Mexican Americans.
- People with a family history of glaucoma. Among Blacks, studies show that glaucoma is:
- Five times more likely to occur in Blacks than in Whites.
- About four times more likely to cause blindness in Blacks than in Whites.
- Fifteen times more likely to cause blindness in Blacks between the ages of 45-64 than in Whites of the same age group.
What are the symptoms?
At first, there are no symptoms. Vision stays normal, and there is no pain.
However, as the disease progresses, a person with glaucoma may notice his or her side vision gradually failing. That is, objects in front may still be seen clearly, but objects to the side may be missed. As the disease worsens, the field of vision narrows and blindness results.
How is it detected?
Many people may know of the “air puff” test or other tests used to measure eye pressure in an eye examination. But, this test alone cannot detect glaucoma. Glaucoma is found most often during an eye examination through dilated pupils. This means drops are put into the eyes during the exam to enlarge the pupils. This allows the eye care professional to see more of the inside of the eye to check for signs of glaucoma.
How can it be treated?
Although open-angle glaucoma cannot be cured, it can usually be controlled. The most common treatments are:
Medications: These may be either in the form of eye drops or pills. Some drugs are designed to reduce pressure by slowing the flow of fluid into the eye. Others help to improve fluid drainage. For most people with glaucoma, regular use of medications will control the increased fluid pressure. But, these drugs may stop working over time. Or, they may cause side effects. If a problem occurs, the eye care professional may select other drugs, change the dose, or suggest other ways to deal with the problem.
Laser surgery: During laser surgery, a strong beam of light is focused on the part of the anterior chamber where the fluid leaves the eye. This results in a series of small changes, which makes it easier for fluid to exit the eye. Over time, the effect of laser surgery may wear off. Patients who have this form of surgery may need to keep taking glaucoma drugs.
Surgery: Surgery can also help fluid escape from the eye and thereby reduce the pressure. However, surgery is usually reserved for patients whose pressure cannot be controlled with eye drops, pills, or laser surgery.
What can you do to protect your vision?
Studies have shown that the early detection and treatment of glaucoma, before it causes major vision loss, is the best way to control the disease. So, if you fall into one of the high-risk groups for the disease, make sure to have your eyes examined through dilated pupils every two years by an eye care professional.
What is Red Eye?
Red Eye or conjunctivitis, describes a group of diseases that cause swelling, itching, burning, and redness of the conjunctiva, the protective membrane that lines the eyelids and covers exposed areas of the sclera, or white of the eye.
Conjunctivitis can spread from one person to another and affects millions of Americans at any given time.
Conjunctivitis can be caused by a bacterial or viral infection, allergy, environmental irritants, a contact lens product, eyedrops, or eye ointments.
At its onset, conjunctivitis is usually painless and does not adversely affect vision. The infection will clear in most cases without requiring medical care. But for some forms of conjunctivitis, treatment will be needed. If treatment is delayed, the infection may worsen and cause corneal inflammation and a loss of vision.
What is Dry Eye?
Dry Eye. The continuous production and drainage of tears is important to the eye’s health. Tears keep the eye moist, help wounds heal, and protect against eye infection. In people with dry eye, the eye produces fewer or less quality tears and is unable to keep its surface lubricated and comfortable.
The tear film consists of three layers–an outer, oily (lipid) layer that keeps tears from evaporating too quickly and helps tears remain on the eye; a middle (aqueous) layer that nourishes the cornea and conjunctiva; and a bottom (mucin) layer that helps to spread the aqueous layer across the eye to ensure that the eye remains wet. As we age, the eyes usually produce fewer tears. Also, in some cases, the lipid and mucin layers produced by the eye are of such poor quality that tears cannot remain in the eye long enough to keep the eye sufficiently lubricated.
The main symptom of dry eye is usually a scratchy or sandy feeling as if something is in the eye. Other symptoms may include stinging or burning of the eye; episodes of excess tearing that follow periods of very dry sensation; a stringy discharge from the eye; and pain and redness of the eye. Sometimes people with dry eye experience heaviness of the eyelids or blurred, changing, or decreased vision, although loss of vision is uncommon.
Dry eye is more common in women, especially after menopause. Surprisingly, some people with dry eye may have tears that run down their cheeks. This is because the eye may be producing less of the lipid and mucin layers of the tear film, which help keep tears in the eye. When this happens, tears do not stay in the eye long enough to thoroughly moisten it.
Dry eye can occur in climates with dry air, as well as with the use of some drugs, including antihistamines, nasal decongestants, tranquilizers, and anti-depressant drugs. People with dry eye should let their health care providers know all the medications they are taking, since some of them may intensify dry eye symptoms.
People with connective tissue diseases, such as rheumatoid arthritis, can also develop dry eye. It is important to note that dry eye is sometimes a symptom of Sjögren’s syndrome, a disease that attacks the body’s lubricating glands, such as the tear and salivary glands. A complete physical examination may diagnose any underlying diseases.
Artificial tears, which lubricate the eye, are the principal treatment for dry eye. They are available over-the-counter as eye drops. Sterile ointments are sometimes used at night to help prevent the eye from drying. Using humidifiers, wearing wrap-around glasses when outside, and avoiding outside windy and dry conditions may bring relief. For people with severe cases of dry eye, temporary or permanent closure of the tear drain (small openings at the inner corner of the eyelids where tears drain from the eye) may be helpful.
What is age-related macular degeneration?
Age-related macular degeneration (AMD) is a disease that blurs the sharp, central vision you need for “straight-ahead” activities such as reading, sewing, and driving. AMD affects the macula, the part of the eye that allows you to see fine detail. AMD causes no pain.
In some cases, AMD advances so slowly that people notice little change in their vision. In others, the disease progresses faster and may lead to a loss of vision in both eyes. AMD is a leading cause of vision loss in Americans 60 years of age and older.
Where is the macula?
The macula is located in the center of the retina , the light-sensitive tissue at the back of the eye. The retina instantly converts light, or an image, into electrical impulses. The retina then sends these impulses, or nerve signals, to the brain.
Are there different forms of AMD?
AMD occurs in two forms: wet and dry.
Wet AMD occurs when abnormal blood vessels behind the retina start to grow under the macula. These new blood vessels tend to be very fragile and often leak blood and fluid. The blood and fluid raise the macula from its normal place at the back of the eye. Damage to the macula occurs rapidly.
With wet AMD , loss of central vision can occur quickly. Wet AMD is considered to beadvanced AMD and is more severe than the dry form.
An early symptom of wet AMD is that straight lines appear wavy. If you notice this condition or other changes to your vision, contact your eye care professional at once. You need a comprehensive dilated eye exam.
Dry AMD occurs when the light-sensitive cells in the macula slowly break down, gradually blurring central vision in the affected eye. As dry AMD gets worse, you may see a blurred spot in the center of your vision. Over time, as less of the macula functions, central vision in the affected eye can be lost gradually.
The most common symptom of dry AMD is slightly blurred vision. You may have difficulty recognizing faces. You may need more light for reading and other tasks. Dry AMD generally affects both eyes, but vision can be lost in one eye while the other eye seems unaffected.
One of the most common early signs of dry AMD is drusen. Drusen are yellow deposits under the retina. They often are found in people over age 60. Your eye care professional can detect drusen during a comprehensive dilated eye exam.
Dry AMD has three stages, all of which may occur in one or both eyes:
- Early AMD . People with early AMD have either several small drusen or a few medium-sized drusen. At this stage, there are no symptoms and no vision loss.
- Intermediate AMD . People with intermediate AMD have either many medium-sized drusen or one or more large drusen. Some people see a blurred spot in the center of their vision. More light may be needed for reading and other tasks.
- Advanced Dry AMD . In addition to drusen, people with advanced dry AMD have a breakdown of light-sensitive cells and supporting tissue in the central retinal area. This breakdown can cause a blurred spot in the center of your vision. Over time, the blurred spot may get bigger and darker, taking more of your central vision. You may have difficulty reading or recognizing faces until they are very close to you.
If you have vision loss from dry AMD in one eye only, you may not notice any changes in your overall vision. With the other eye seeing clearly, you still can drive, read, and see fine details. You may notice changes in your vision only if AMD affects both eyes. If blurriness occurs in your vision, see an eye care professional for a comprehensive dilated eye exam.
Do drusen cause vision loss in advanced dry AMD?
Drusen alone do not usually cause vision loss. In fact, scientists are unclear about the connection between drusen and AMD. They do know that an increase in the size or number of drusen raises a person’s risk of developing either advanced dry AMD or wet AMD . These changes can cause serious vision loss.
The dry form has early and intermediate stages. Does the wet form have similar stages?
No. The wet form is considered advanced AMD .
Can advanced AMD be either the dry form or the wet form?
Yes. Both the wet form and the advanced dry form are considered advanced AMD . Vision loss occurs with either form. In most cases, only advanced AMD can cause vision loss.
People who have advanced AMD in one eye are at especially high risk of developingadvanced AMD in the other eye.
Which is more common–the dry form or the wet form?
The dry form is much more common. More than 85 percent of all people withintermediate and advanced AMD combined have the dry form.
However, if only advanced AMD is considered, about two-thirds of patients have thewet form . Because almost all vision loss comes from advanced AMD , the wet formleads to significantly more vision loss than the dry form .
Can the dry form turn into the wet form?
Yes. All people who have the wet form had the dry form first.
The dry form can advance and cause vision loss without turning into the wet form . The dry form also can suddenly turn into the wet form , even during early stage AMD . There is no way to tell if or when the dry form will turn into the wet form .
Who is at risk for AMD?
AMD can occur during middle age. The risk increases with aging. Other risk factors include:
- Obesity. Research studies suggest a link between obesity and the progression of early and intermediate stage AMD to advanced AMD.
- Race. Whites are much more likely to lose vision from AMD than African Americans.
- Family history. People with a family history of AMD are at higher risk of getting the disease.
- Gender. Women appear to be at greater risk than men.
How is AMD detected?
AMD is detected during a comprehensive eye exam that includes:
- Visual acuity test . This eye chart test measures how well you see at various distances.
- Dilated eye exam. Drops are placed in your eyes to widen, or dilate, the pupils. Your eye care professional uses a special magnifying lens to examine your retina and optic nerve for signs of AMD and other eye problems. After the exam, your close-up vision may remain blurred for several hours.
- Tonometry. An instrument measures the pressure inside the eye. Numbing drops may be applied to your eye for this test.
Your eye care professional also may do other tests to learn more about the structure and health of your eye.
During an eye exam, you may be asked to look at an Amsler grid . The pattern of the grid resembles a checkerboard. You will cover one eye and stare at a black dot in the center of the grid. While staring at the dot, you may notice that the straight lines in the pattern appear wavy. You may notice that some of the lines are missing. These may be signs of AMD.
If your eye care professional believes you need treatment for wet AMD , he or she may suggest a fluorescein angiogram . In this test, a special dye is injected into your arm. Pictures are taken as the dye passes through the blood vessels in your retina. The test allows your eye care professional to identify any leaking blood vessels and recommend treatment.
What is diabetic retinopathy?
Diabetic retinopathy is a complication of diabetes and a leading cause of blindness. It occurs when diabetes damages the tiny blood vessels inside the retina, the light-sensitive tissue at the back of the eye. A healthy retina is necessary for good vision.
If you have diabetic retinopathy, at first you may notice no changes to your vision. But over time, diabetic retinopathy can get worse and cause vision loss. Diabetic retinopathy usually affects both eyes.
What are the stages of diabetic retinopathy?
Diabetic retinopathy has four stages:
- Mild nonproliferative retinopathy: At this earliest stage, microaneurysms occur. They are small areas of balloon-like swelling in the tiny blood vessels of the retina.
- Moderate nonproliferative retinopathy: As the disease progresses, some blood vessels that nourish the retina are blocked.
- Severe nonproliferative retinopathy: Many more blood vessels are blocked, depriving several areas of the retina of their blood supply. These areas of the retina send signals to the body to grow new blood vessels for nourishment.
- Proliferative retinopathy: At this advanced stage, the signals sent by the retina for nourishment trigger the growth of new blood vessels. This condition is called proliferative retinopathy. These new blood vessels are abnormal and fragile. They grow along the retina and along the surface of the clear, vitreous gel that fills the inside of the eye. (See diagram above.)
By themselves, these blood vessels do not cause symptoms or vision loss. However, they have thin, fragile walls. If they leak blood, severe vision loss and even blindness can occur.
How does diabetic retinopathy cause vision loss?
Blood vessels damaged from diabetic retinopathy can cause vision loss in two ways:
- Fragile, abnormal blood vessels can develop and leak blood into the center of the eye, blurring vision. This is proliferative retinopathy and is the fourth and most advanced stage of the disease.
- Fluid can leak into the center of the macula, the part of the eye where sharp, straight-ahead vision occurs. The fluid makes the macula swell, blurring vision. This condition is called macular edema . It can occur at any stage of diabetic retinopathy, although it is more likely to occur as the disease progresses. About half of the people with proliferative retinopathy also have macular edema.
Does diabetic retinopathy have any symptoms?
Diabetic retinopathy often has no early warning signs. Don’t wait for symptoms. Be sure to have a comprehensive dilated eye exam at least once a year.
Who is at risk for diabetic retinopathy?
All people with diabetes, both type 1 and type 2, are at risk, which is why everyone with diabetes should get a comprehensive dilated eye exam at least once a year.
Between 40 to 45 percent of Americans diagnosed with diabetes have some stage of diabetic retinopathy. If you have diabetic retinopathy, your eye care professional can recommend treatment to help prevent its progression.
During pregnancy, diabetic retinopathy may be a problem for women with diabetes. To protect vision, every pregnant woman with diabetes should have a comprehensive dilated eye exam as soon as possible. Your eye care professional may recommend additional exams during your pregnancy.
What is computer vision syndrome?
As people spend more time each day working on computers, eye-care professionals are seeing an increasing number of patients with a group of symptoms that are now collectively referred to as computer vision syndrome. The more time you spend working at a computer screen, the more likely you are to be experiencing some or all of these symptoms.
What causes it?
Characters on a screen are much more difficult for our eyes to focus on than are characters on a printed page. Unlike printed characters, screen characters do not have well defined edges and are not of equal density. This makes it difficult for our eyes to maintain focus and they tend to move to a point known as the resting point of accommodation. the resting point of accommodation is where your eyes focus when you don’t have anything to look at.
The continual refocusing that occurs as your eyes move to their resting point and then strain to quickly regain focus on the screen characters makes reading from a screen more difficult and tiring than reading printed text.
What are the symptoms of computer vision syndrome?
Computer vision syndrome takes a variety of forms. Most frequently people experience one or several of the following symptoms:
- Tired eyes
- Blurred vision
- Double vision
- Neck and shoulder pain
How can it be treated?
There are several approaches to treating computer vision syndrome all of which can be provided by your eye-care professional.
Comprehensive treatment requires a thorough eye examination to diagnose and correct vision problems. The use of specially designed computer glasses may be required. Computer glasses differ from regular glasses because the distance between your eyes and a computer screen is usually different than the distance between your eyes and printed materials that you work with.
Additionally, a review of your work environment and work habits may be necessary to help you correct lighting and postural factors that may be contributing to computer vision syndrome.
What is a Cataract?
A cataract is a clouding of the lens in the eye that affects vision. Most cataracts are related to aging. Cataracts are very common in older people. By age 80, more than half of all Americans either have a cataract or have had cataract surgery. A cataract can occur in either or both eyes. It cannot spread from one eye to the other.
What is the Lens?
The lens is a clear part of the eye that helps to focus light, or an image, on the retina. The retina is the light-sensitive tissue at the back of the eye. In a normal eye, light passes through the transparent lens to the retina. Once it reaches the retina, light is changed into nerve signals that are sent to the brain. The lens must be clear for the retina to receive a sharp image. If the lens is cloudy from a cataract, the image you see will be blurred.
Age-related cataracts develop in two ways:
- Clumps of protein reduce the sharpness of the image reaching the retina. The lens consists mostly of water and protein. When the protein clumps up, it clouds the lens and reduces the light that reaches the retina. The clouding may become severe enough to cause blurred vision. Most age-related cataracts develop from protein clumpings. When a cataract is small, the cloudiness affects only a small part of the lens. You may not notice any changes in your vision. Cataracts tend to “grow” slowly, so vision gets worse gradually. Over time, the cloudy area in the lens may get larger, and the cataract may increase in size. Seeing may become more difficult. Your vision may get duller or blurrier.
- The clear lens slowly changes to a yellowish/brownish color, adding a brownish tint to vision. As the clear lens slowly colors with age, your vision gradually may acquire a brownish shade. At first, the amount of tinting may be small and may not cause a vision problem. Over time, increased tinting may make it more difficult to read and perform other routine activities. This gradual change in the amount of tinting does not affect the sharpness of the image transmitted to the retina. If you have advanced lens discoloration, you may not be able to identify blues and purples. You may be wearing what you believe to be a pair of black socks, only to find out from friends that you are wearing purple socks.
Who is at risk for cataracts?
The risk of cataract increases as you get older. Other risk factors for cataract include:
- Certain diseases (for example, diabetes).
- Personal behavior (smoking, alcohol use).
- The environment (prolonged exposure to ultraviolet sunlight).