amblyopia

Amblyopia, or "lazy eye," is the most common cause of visual impairment in children. It happens when an eye fails to work properly with the brain. The eye may look normal, but the brain favors the other eye. In some cases, it can affect both eyes. Causes include:

• Strabismus - a disorder in which the two eyes don't line up in the same direction
• Refractive error in an eye - when one eye cannot focus as well as the other, because of a problem with its shape. This includes nearsightedness, farsightedness, and astigmatism.
• Cataract - a clouding in the lens of the eye

It can be hard to diagnose amblyopia. It is often found during a routine vision exam.

Treatment for amblyopia forces the child to use the eye with weaker vision. There are two common ways to do this. One is to have the child wear a patch over the good eye for several hours each day, over a number of weeks to months. The other is with eye drops that temporarily blur vision. Each day, the child gets a drop of a drug called atropine in the stronger eye. It is also sometimes necessary to treat the underlying cause. This could include glasses or surgery.

NIH: National Eye Institute

Some eye problems are minor and don't last long. But some can lead to a permanent loss of vision.

Common eye problems include:

• Refractive errors
• Cataracts - clouded lenses
• Optic nerve disorders, including glaucoma
• Retinal disorders - problems with the nerve layer at the back of the eye
• Macular degeneration - a disease that destroys sharp, central vision
• Diabetic eye problems
• Conjunctivitis - an infection also known as pink eye

Your best defense is to have regular checkups, because eye diseases do not always have symptoms. Early detection and treatment could prevent vision loss. See an eye care professional right away if you have a sudden change in vision, if everything looks dim, or if you see flashes of light. Other symptoms that need quick attention are pain, double vision, fluid coming from the eye, and inflammation.

NIH: National Eye Institute

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