amaurosis

Vision impairment is the loss of vision. It includes blindness, which means that you have lost all or most of your sight. It also includes low vision, which means you have some vision, but the vision loss makes it hard to do everyday activities. You may have trouble reading, shopping, cooking, writing, and watching TV. Low vision can't be fixed with glasses, contact lenses, medicine, or surgery.

Aging doesn't cause vision loss on its own. But many diseases that are more common in older adults can cause it. The leading causes of low vision and blindness in the United States are age-related eye diseases such as macular degeneration, cataracts, and glaucoma. Other eye disorders, eye injuries, and birth defects can also cause vision loss.

Vision impairment is diagnosed with a dilated eye exam. Early warning signs of a vision problem can include not being able to see well enough to:

• Do everyday tasks like reading and driving
• Recognize people's faces
• Tell the difference between colors
• See the television or computer screen clearly

You can have these symptoms even though you are wearing glasses or contacts.

There are several types of low vision. Which type you have depends on the condition that caused your low vision.

Common types of low vision include:

• Central vision loss (not being able to see things in the center of your vision)
• Peripheral (side) vision loss (not being able to see things out of the corners of your eyes)
• Night blindness (not being able to see in low light)
• Blurry or hazy vision

Low vision is permanent. Glasses, medicine, and surgery can't cure low vision. But sometimes they can improve your vision, help you do everyday activities more easily, or keep your remaining vision.

Your treatment options will depend on the condition that caused your low vision. Ask your eye doctor which treatments might help you. They may recommend vision aids or vision rehabilitation, which might make everyday activities easier.

Vision rehabilitation teaches you how to live with your vision loss. It may include:

• Showing you how to use a magnifying device or screen readers for reading
• Helping you set up your home so you can move around more easily
• Employment and job training
• Assistive devices, like lighting and reading stands

Your provider may suggest other resources, such as transportation and household services, to help you cope with your vision loss.

The sooner vision loss or eye disease is found and treated, the greater your chances of keeping your remaining vision. Whatever the cause, lost vision cannot be restored. But it can be managed. A loss of vision means you may have to reorganize your life and learn new ways of doing things. Your provider may make suggestions to help make life easier. These may include:

If you have some vision:

• Visual aids such as magnifiers
• Telescopic glasses or monoculars for seeing distance
• Large print books
• Clocks with larger numbers
• Brighter lights
• Anti-glare sunglasses or glare shields

If you have no vision (blindness):

• Devices like text-reading software and braille books

You can help take care of your vision by:

• Having regular comprehensive eye exams by an eye care professional
• Wearing sunglasses and protective eyewear to protect your eyes
• Making lifestyle changes to lower your risk of health conditions that can cause vision problems:
  • Getting regular physical activity
  • Staying at a healthy weight
  • Quitting smoking (or not starting)
  • Eating a healthy diet

NIH: National Eye Institute

Most of us see our world in color. We enjoy looking at a lush green lawn or a red rose in full bloom. If you have a color vision defect, you may see these colors differently than most people.

There are three main kinds of color vision defects. Red-green color vision defects are the most common. This type occurs in men more than in women. The other major types are blue-yellow color vision defects and a complete absence of color vision.

Most of the time, color blindness is genetic. There is no treatment, but most people adjust and the condition doesn't limit their activities.

Diabetes is a disease in which your blood glucose, or blood sugar, levels are too high. Glucose comes from foods you eat. The cells of your body need glucose for energy. A hormone called insulin helps the glucose get into your cells.

With type 1 diabetes, your body doesn't make insulin. With type 2 diabetes, your body doesn't make or use insulin well. Without enough insulin, glucose builds up in your blood and causes high blood glucose levels.

Over time, high blood glucose may damage the blood vessels and lenses in your eyes. This can lead to serious diabetic eye problems which can harm your vision and sometimes cause blindness. Some common diabetic eye problems include:

• Diabetic retinopathy, which is the leading cause of blindness in American adults. It affects blood vessels in the retina (the light-sensitive layer of tissue in the back of your eye). The blood vessels may swell and leak fluid into your eye. If it's not treated, it can cause serious problems such as vision loss and retinal detachment, where the retina is pulled away from its normal position at the back of your eye.
• Diabetic macular edema (DME), which happens when blood vessels in the retina leak fluid into the macula (the part of the retina needed for sharp, central vision). This usually develops in people who already have other signs of diabetic retinopathy.
• Glaucoma, a group of eye diseases that can damage the optic nerve (the bundle of nerves that connects the eye to the brain). Glaucoma from diabetes happens when the blood vessels in the front of your eye are damaged, and new blood vessels grow near the iris (the colored part of your eye). The blood vessels block the space where fluid drains from your eye. This causes fluid to build up and pressure to increase inside your eye.
• Cataract, which is the leading cause of blindness worldwide. It happens when the clear lens in the front of your eye becomes cloudy. Cataracts are common as people age. But people with diabetes are more likely to develop cataracts younger and faster than people without diabetes. Researchers think that high glucose levels cause deposits to build up in the lenses of your eyes.

Anyone with diabetes can develop diabetic eye disease. But your risk of developing it is higher if you have diabetes and:

• Have had diabetes for a long time
• Don't have good control over your high blood glucose or high blood pressure
• Are pregnant
• Have high blood cholesterol
• Smoke tobacco

In the early stages, diabetic eye problems usually don't have any symptoms. That's why regular dilated eye exams are so important, even if you think your eyes are healthy.

You should also watch for sudden changes in your vision that could be signs of an emergency. Call your eye care professional right away if you notice any of these symptoms:

• Many new spots or dark wavy strings floating in your vision (floaters)
• Flashes of light
• A dark shadow over part of your vision, like a curtain
• Vision loss
• Eye pain or redness

Talk with your eye care professional if you have these symptoms, even if they come and go:

• Spots or dark wavy strings floating in your vision
• Blurry or wavy vision
• Vision that changes a lot
• Trouble seeing colors

Eye care professionals do dilated eye exams to diagnose eye problems. A dilated eye exam uses eye drops to open your pupils wide so your eye care professional can look for signs of eye problems and treat them before they harm your vision. They will also test your vision and measure the pressure in your eyes.

Treatment for diabetic eye problems depends on the problem and how serious it is. Some of the treatments include:

• Lasers to stop blood vessels from leaking
• Injections (shots) in the eye to stop new, leaky blood vessels from growing
• Surgery to remove blood and scar tissue or replace a cloudy lens
• Eye drops to lower fluid pressure in the eye

But these treatments aren't cures. Eye problems can come back. That's why your best defense against serious vision loss is to take control of your diabetes and get regular eye exams. It's also important to keep your blood pressure and cholesterol in a healthy range.

NIH: National Institute of Diabetes and Digestive and Kidney Diseases

The retina is a layer of tissue in the back of your eye that senses light and sends images to your brain. In the center of this nerve tissue is the macula. It provides the sharp, central vision needed for reading, driving and seeing fine detail.

Retinal disorders affect this vital tissue. They can affect your vision, and some can be serious enough to cause blindness. Examples are:

• Macular degeneration - a disease that destroys your sharp, central vision
• Diabetic eye disease
• Retinal detachment - a medical emergency, when the retina is pulled away from the back of the eye
• Retinoblastoma - cancer of the retina. It is most common in young children.
• Macular pucker - scar tissue on the macula
• Macular hole - a small break in the macula that usually happens to people over 60
• Floaters - cobwebs or specks in your field of vision

NIH: National Eye Institute

Glaucoma is a group of diseases that can damage the optic nerve of one, or both, of your eyes. This can result in vision loss. There are different types of glaucoma, but the most common type is open-angle glaucoma. Other less common types include angle-closure glaucoma, and congenital glaucoma.

You may not have any symptoms of glaucoma. Regular eye exams by an eye care provider can check for glaucoma and other eye problems to help protect your vision. Treatments that lower eye pressure help slow the disease. Without treatment, glaucoma can eventually lead to blindness.

Medical experts aren't sure what causes glaucoma, but the most common types usually happen when the fluid pressure inside your eye slowly rises, damaging the optic nerve. Other types of glaucoma may be caused by medical conditions, or a baby may be born with it.

Not everyone with high eye pressure develops glaucoma. Some people may even get glaucoma with normal eye pressure. The amount of pressure your optic nerve can handle is different for each person. Getting regular dilated eye exams helps your provider figure out what level of eye pressure is normal for you.

Often there are no symptoms of glaucoma at first. Or symptoms may start so slowly that you may not notice them. Without treatment, you slowly lose your peripheral (side) vision. It may seem like you're looking through a tunnel. Over time, your straight-ahead vision may decrease until no vision remains.

If you have sudden symptoms of intense eye pain, blurry vision, red eyes, or an upset stomach (nausea), you need to go to your eye care provider or an emergency room right away. These could be symptoms of angle-closure glaucoma. This less common type of glaucoma causes fluid to build up quickly in your eye.

A comprehensive eye exam can tell if you have glaucoma. This would include:

• A dilated eye exam. This involves getting eye drops that dilate (widen) your pupils. This allows more light to enter your eye. Your eye care provider examines your eyes using a special magnifying lens. This provides a clear view of important tissues at the back of your eye to check for glaucoma or other eye problems. For a few hours after the exam your vision may be blurry and sensitive to light, so you will need someone to take you home.
• Visual field testing. This check of your peripheral (side) vision allows your eye care provider to find out how well you can see objects off to the side of your vision without moving your eyes.
• Tonometry. This measures the pressure inside your eye.

If you're at higher risk for glaucoma, you should get comprehensive eye exams every one to two years. You're at higher risk if you:

• Are Black or African American and over age 40
• Are over age 60, especially if you're Hispanic or Latino
• Have a family history of glaucoma

You're also at higher risk if you have high blood pressure or diabetes and should get a dilated eye exam at least once a year. Talk with your provider about your risk and how often you should get your eyes checked.

Early treatment can help protect your eyes against vision loss. There is no cure, but glaucoma can usually be controlled. Without treatment it can eventually cause blindness. Treatments can include:

• Prescription eye drops are the most common treatment to lower the pressure in your eye and prevent damage to your optic nerve.
• Other treatments may include oral medicines, laser treatment, and/or surgery.

A combination of these treatments may be used to lower eye pressure and help drain the fluid out of your eye.

There is no way to prevent glaucoma. Eye exams can help find glaucoma or other eye problems before they can affect your vision. If you have glaucoma, be sure to continue with treatment to prevent your vision from getting worse.

NIH: National Eye Institute

Behcet's syndrome is a disease that involves vasculitis, which is inflammation of the blood vessels. It causes problems in many parts of the body. The most common symptoms are:

• Sores in the mouth
• Sores on the sex organs
• Other skin sores
• Swelling of parts of the eye
• Pain, swelling and stiffness of the joints

More serious problems can include meningitis, blood clots, inflammation of the digestive system and blindness.

Doctors aren't sure what causes Behcet's. It is rare in the United States, but is common in the Middle East and Asia. It mainly affects people in their 20s and 30s. Diagnosing Behcet's can take a long time, because symptoms may come and go, and it may take months or even years to have all of the symptoms. There is no cure. Treatment focuses on reducing pain and preventing serious problems. Most people can control symptoms with treatment.

NIH: National Institute of Arthritis and Musculoskeletal and Skin Diseases

Developmental disabilities are conditions that are usually present at birth. They can affect a child's growth and development. These conditions can cause physical, learning, language, or behavior issues. They can include:

• Learning disabilities. These conditions affect the ability to learn.
• Autism spectrum disorder (ASD). This is a disorder that affects behavior, communication, and social skills.
• Cerebral palsy (CP). This is a condition that affects movement, coordination, and balance.
• Physical disabilities. These could include blindness or deafness.
• Conditions that can affect both physical and mental abilities. This could include Down syndrome.

These conditions can cause lifelong challenges in learning. Completing daily tasks may be difficult. Early treatment may help your child learn important skills and make the most of their strengths.

Developmental disabilities are often present at birth. They can occur due to various reasons. These can include:

• Genetic or chromosome abnormalities. These cause conditions such as Down syndrome, Fragile-X-Syndrome, and Rett syndrome.
• Use of substances while pregnant. For example, drinking alcohol when pregnant can cause fetal alcohol spectrum disorders.
• Certain infections during pregnancy.
• Preterm birth or low birth weight.

The way a developmental disability is diagnosed depends on the condition. Screening tests or a physical exam may be done to check for a medical problem. Other tests and questionnaires may help find out if your child has a developmental disability. These may include:

• Screening tests that are done during pregnancy or for newborns
• Developmental and behavioral screening tests or questionnaires to check if your child is developing on schedule
• Observing your child's behavior and how they interact with other people
• Testing your child's intellectual and school performance
• Asking about your family history

If your child has a developmental disability, these are usually lifelong conditions. Often, there is no cure, but treatment can help the symptoms. Treatments can include:

• Physical, speech, and occupational therapy
• Special teaching methods
• Psychological counseling
• To keep track of how your child grows and changes over time

NIH: National Institute of Child Health and Human Development

Your eyes are an important part of your health. Most people rely on their eyes to see and make sense of the world around them. But some eye diseases can lead to vision loss, so it is important to identify and treat eye diseases as early as possible. You should get your eyes checked as often as your health care provider recommends it, or if you have any new vision problems. And just as it is important to keep your body healthy, you also need to keep your eyes healthy.

There are things you can do to help keep your eyes healthy and make sure you are seeing your best:

• Eat a healthy, balanced diet. Your diet should include plenty or fruits and vegetables, especially deep yellow and green leafy vegetables. Eating fish high in omega-3 fatty acids, such as salmon, tuna, and halibut can also help your eyes.
• Maintain a healthy weight. Being overweight or having obesity increases your risk of developing diabetes. Having diabetes puts you at higher risk of getting diabetic retinopathy or glaucoma.
• Get regular exercise. Exercise may help to prevent or control diabetes, high blood pressure, and high cholesterol. These diseases can lead to some eye or vision problems. So if you exercise regularly, you can lower your risk of getting these eye and vision problems.
• Wear sunglasses.Sun exposure can damage your eyes and raise your risk of cataracts and age-related macular degeneration. Protect your eyes by using sunglasses that block out 99 to 100% of both UV-A and UV-B radiation.
• Wear protective eye wear. To prevent eye injuries, you need eye protection when playing certain sports, working in jobs such as factory work and construction, and doing repairs or projects in your home.
• Avoid smoking. Smoking increases the risk of developing age-related eye diseases such as macular degeneration and cataracts and can damage the optic nerve.
• Know your family medical history. Some eye diseases are inherited, so it is important to find out whether anyone in your family has had them. This can help you determine if you are at higher risk of developing an eye disease.
• Know your other risk factors. As you get older, you are at higher risk of developing age-related eye diseases and conditions. It is important to know your risk factors because you may be able to lower your risk by changing some behaviors.
• If you wear contacts, take steps to prevent eye infections. Wash your hands well before you put in or take out your contact lenses. Also follow the instructions on how to properly clean them, and replace them when needed.
• Give your eyes a rest. If you spend a lot of time using a computer, you can forget to blink your eyes and your eyes can get tired. To reduce eyestrain, try the 20-20-20 rule: Every 20 minutes, look away about 20 feet in front of you for 20 seconds.

Everyone needs to have their eyesight tested to check for vision and eye problems. Children usually have vision screening in school or at their health care provider's office during a checkup. Adults may also get vision screenings during their checkups. But many adults need more than a vision screening. They need a comprehensive dilated eye exam.

Getting comprehensive dilated eye exams is especially important because some eye diseases may not have warning signs. The exams are the only way to detect these diseases in their early stages, when they are easier to treat.

The exam includes several tests:

• A visual field test to measure your side (peripheral) vision. A loss of peripheral vision may be a sign of glaucoma.
• A visual acuity test, where you read an eye chart about 20 feet away, to check on how well you see at various distances
• Tonometry, which measures your eye's interior pressure. It helps to detect glaucoma.
• Dilation, which involves getting eye drops that dilate (widen) your pupils. This allows more light to enter the eye. Your eye care provider examines your eyes using a special magnifying lens. This provides a clear view of important tissues at the back of your eye, including the retina, macula, and optic nerve.

If you have a refractive error and are going to need glasses or contacts, then you will also have a refraction test. When you have this test, you look through a device that has lenses of different strengths to help your eye care professional figure out which lenses will give you the clearest vision.

At what age you should start getting these exams and how often you need them depends on many factors. They include your age, race, and overall health. For example, if you are African American, you are at higher risk of glaucoma and you need to start getting the exams earlier. If you have diabetes, you should get an exam every year. Check with your health care provider about if and when you need these exams.

Even if your eyes feel healthy, you could have a problem and not know it. That's why regular eye exams are so important. Refractive errors are the most common type of vision problem that makes it hard to see clearly. But some eye conditions or diseases don't have any symptoms and can lead to a permanent loss of vision.

Some common eye diseases and conditions include:

• Cataracts, which happens when the clear lens in the front of your eye becomes cloudy. Cataracts are common as you get older and can lead to vision loss.
• Optic nerve disorders, which includes glaucoma. Glaucoma usually happens when the fluid pressure inside your eyes slowly rises.
• Retinal disorders, which are problems with the nerve layer at the back of your eye.
• Macular degeneration, which is a disease that destroys your sharp, central vision.
• Diabetic eye problems, which can cause vision loss and blindness.
• Conjunctivitis, which is an infection also known as pink eye. It can cause pink or red itchy eyes. Some types of pink eye can spread very easily.

Some eye conditions and diseases do not always have symptoms. Early detection through a comprehensive dilated eye exam could help your eye care provider detect diseases in the early stages. Proper treatment could help slow or prevent vision loss.

Get regular eye exams and call your eye care professional right away if you notice any of these symptoms:

• A sudden change in vision
• Everything looks dim
• Flashes of light
• Eye pain
• Double vision
• Fluid coming from your eye
• Inflammation (swelling)

Getting older increases your risk of some eye diseases. Other things that may put you at a higher risk of some eye diseases can include if you:

• Are overweight or obese
• Have a family history of eye disease
• Are African American, Hispanic, or Native American
• Have certain health conditions such as Diabetic eye problems, or high blood pressure

Treatment may depend on the eye condition or disease but can include:

• A new prescription for eyeglasses or contacts
• Use of bright lights or magnifying lenses for reading and other activities
• Medicines
• Prescription eye drops or ointments
• Laser treatment
• Surgery

Depending on your eye condition or disease, treatment may slow vision loss but may not restore vision. Talk to your provider about what treatment is best for you.

Your best defense is to have regular checkups. Be sure to tell your provider if any eye diseases run in your family.

You can also help take care of your vision by making lifestyle changes to lower your risk of health conditions that can cause vision problems. This could include by:

• Protecting your eyes from the sun
• Wearing protective eyewear while using tools or playing certain sports
• Getting regular physical activity
• Staying at a healthy weight
• Quitting smoking (or not starting)
• Eating a healthy diet

NIH: National Eye Institute

The optic nerve is a bundle of more than 1 million nerve fibers that carry visual messages. You have one connecting the back of each eye (your retina) to your brain. Damage to an optic nerve can cause vision loss. The type of vision loss and how severe it is depends on where the damage occurs. It may affect one or both eyes.

There are many different types of optic nerve disorders, including:

• Glaucoma is a group of diseases that are the leading cause of blindness in the United States. Glaucoma usually happens when the fluid pressure inside the eyes slowly rises and damages the optic nerve.
• Optic neuritis is an inflammation of the optic nerve. Causes include infections and immune-related illnesses such as multiple sclerosis. Sometimes the cause is unknown.
• Optic nerve atrophy is damage to the optic nerve. Causes include poor blood flow to the eye, disease, trauma, or exposure to toxic substances.
• Optic nerve head drusen are pockets of protein and calcium salts that build up in the optic nerve over time

Contact your health care provider if you are having vision problems. Tests for optic nerve disorders may include eye exams, ophthalmoscopy (an examination of the back of your eye), and imaging tests. Treatment depends on which disorder that you have. With some optic nerve disorders, you may get your vision back. With others, there is no treatment, or treatment may only prevent further vision loss.