Some of the most common eye problems are refractive errors. These are the problems that eye doctors check for routinely in a vision test. Refraction means bending of light rays to focus the light coming from an image. Refractive errors are problems with the focusing of the eye, because of the way the eye is shaped, which causes the image you see to be blurred.
Refractive errors include:
- Astigmatism. In astigmatism, there's a problem with the curve of the cornea. This causes part of the eye's image to be blurry. Corrective lenses such as contact lenses or glasses can usually correct vision in people with astigmatism.
- Nearsightedness. Also called myopia or shortsightedness, nearsightedness occurs when the eye focuses the image of an object in front of the retina instead of directly on it. In most cases, people can't see well far away, but can see objects clearly close up. The condition tends to get somewhat worse through childhood and adolescence, but stabilizes in adulthood. People with this condition may need to wear glasses or contacts to correct their vision. Laser eye surgery is now commonly used in adults to correct nearsightedness permanently by changing the shape of the cornea. Laser surgery is not used in kids and teens because the eye may still be growing and the refractive error changing.
- Farsightedness. Also called hyperopia or longsightedness, farsightedness occurs when the incoming image is not focused on the retina, but behind it. This makes it difficult to see close objects clearly, even though far-off objects can be seen clearly. Glasses or contact lenses can correct this problem in kids and teens. Most adults develop a form of farsightedness called presbyopia as they get older.
Some of the other eye problems that can affect children and teens include:
Blindness. This is the loss of useful sight. Blindness can be temporary or permanent and it has many causes. Birth defects or damage to any portion of the eye, the optic nerve, or the area of the brain responsible for vision can lead to blindness. The visual impairment cannot be corrected with surgery or corrective lenses, and the condition can make it difficult to perform everyday activities. Diabetes, problems with the macula, and eye changes because of aging account for most blindness in the United States.
Cataracts. Some children are born with cataracts, a cloudiness of the eye's lenses that prevent images from being seen clearly or at all. But cataracts are much more prevalent in the elderly among whom surgery to remove cataracts and correct vision is common. In infants and young children, cataracts must be treated to prevent permanent problems with development of vision.
Color blindness. Color blindness is caused by problems in the pigments of the cones in the retina. Most people who are color-blind can see some colors. In most cases, someone who is color-blind confuses some colors with others, usually red and green. People can be born color-blind or they may develop the condition over time. The most common form of color blindness is an inherited condition that affects boys much more often than girls. Color blindness cannot be corrected.
Conjunctivitis. Conjunctivitis refers to inflammation (redness, pain, and swelling) of the conjunctiva. One type of conjunctivitis is called pinkeye, a common contagious infection in which the eyes become pinkish red and watery, and pus may form. Pinkeye is usually treated with eyedrops. Conjunctivitis may also occur due to allergies or from a scratch on the surface of the eye.
Dacryostenosis. Dacryostenosis is a blockage of the tear drainage system of the eye occurring in the lower eyelid. This is a fairly common problem in infants, but often improves with time.
Eye injuries. Injuries to the eye are one of the most common preventable causes of blindness. Eye injuries may be caused by irritants such as sand, dirt, or other foreign bodies on the eye's surface. Chemicals or foreign bodies that become embedded in the eye can also cause pain and loss of vision. Forceful blows to the eye can cause bleeding inside the eye and damage to the cornea, retina, and other important eye structures.
Glaucoma. One of the leading causes of blindness in the United States, glaucoma is a disorder that causes fluid pressure to build up inside the eye, potentially causing damage to the optic nerve. Although it can occur in infants and children, it is much more common among older adults. Unless detected early by routine screening tests, it usually goes undiagnosed until some vision is lost.
Macular degeneration is an eye disease that mainly affects older people. But sometimes infants and children can develop it, too. When someone has macular degeneration, the middle area of the retina becomes scarred. This causes eyesight to deteriorate over many years. The cause of macular degeneration is unknown in most cases, but it tends to run in families, which indicates that genes and heredity are involved.
Retinoblastoma. This is a cancerous tumor in the eye that usually appears in the first 5 years of life. There may be permanent vision loss, and the affected eye(s) may have to be removed.
Retinopathy of prematurity. Premature babies sometimes have damage to the blood vessels in the eye's retina, a condition known as retinopathy of prematurity, which can lead to severe vision loss in some cases.
Strabismus. A condition in which the eyes appear crossed, strabismus is usually caused by a defect in the balance of the pull exerted by the muscles that help the eyes stay straight and move together properly. Surgery on the eye muscles can help realign the eyes. Permanent vision loss in the less-used eye (amblyopia) can occur if the condition is not treated in early childhood.
Sty. A sty is an infection of one of the follicles from which the eyelashes grow. Sties are treated by applying warm compresses and using antibiotics.
Proper care of your child's eyes includes having periodic eye exams at routine office checkups and by an eye specialist according to the schedule recommended by your doctor. Signs that a very young child may be having vision trouble include constant eye rubbing, tearing or redness, and trouble following an object. Older kids may squint or sit too close to the TV. Kids who are having trouble seeing might also complain of headaches at the end of the day.