Changes in vision can range from mild to severe, and may be lasting or only temporary. For example, a person may become completely blind or may have poor vision only under certain conditions.
Common vision changes can include - but are not limited to: blurry visiondouble visioncloudy vision
Vision changes can be caused by anything from normal aging to life-threatening conditions. The exact changes in the body will depend on the specific cause and type of vision change.
Kinds of vision changes include: decreased sharpness of vision, which means either being unable to focus on objects up close or far away, or bothdouble vision, which means seeing two of everythingloss of peripheral (side) visiontotal loss of vision (blindness)cloudy vision, which feels as though the person is looking through a dirty windshield"blind spots," which means the person has areas of vision where he or she can only see blackness
The possible causes of vision changes include: refractive errors, such as being nearsighted, farsighted or having presbyopia. A person with presbyopia has a hard time seeing things up close, due to age-related changes in the eye. This condition affects most people over age 50. This is the reason older people often need bifocals or reading glasses.infections of the eye, such as conjunctivitis or keratitiscataracts, a common condition in older adults caused by changes in the lens of the eyeglaucoma, a condition caused by increased pressure within the eyedamage or inflammation of the nerves of the eyedamage to the vision areas of the brain, due to a stroke or brain tumordamage to the retina, the part of the eye that is similar to the film inside a camera. The retina can be damaged in diabetes, macular degeneration, or retinal detachment.trauma, or injury, to the eyestrabismus, sometimes known as lazy eye, in which the eyes fail to line up properlytemporal arteritis, an inflammation of the arteries that supply blood to the eyevitamin A deficiencymedicines, such as the heart medicine digoxin (i.e., Lanoxin), or the antibiotic ethambutol (i.e., Myambutol)
Other causes of vision changes are possible. Sometimes, no cause can be found.
Prevention depends on the cause. Early detection and treatment of glaucoma can often prevent vision loss. Control of diabetes can help prevent vision changes caused by diabetic retinopathy. Frequent hand washing and not touching the eyes with the hands helps prevent conjunctivitis. Many cases of vision changes cannot be prevented.
Any change in vision should be evaluated medically. A history and physical exam, including an examination of the eye, are done first. In an eye exam, the person may be asked to read an eye chart. Special instruments may be used, and the pressure inside the eye may be measured. Eye drops can be put into the eye to make the pupils get bigger. This helps the eye care professional see the inside of the eye better.
The eye care professional will need to know the kind of vision changes the person has noticed. He or she will also ask: when the vision change startedwhether it came on quickly or slowlywhether one or both eyes are affectedwhether near vision, far vision, or both, is affectedwhether there is any pain associated with the vision changewhat medicines the person takeswhat other medical conditions the person haswhether there is any family history of vision changes
In addition, the eye care professional may ask about other symptoms, such as: headachenauseavomitingweaknessmuscle pains
In some cases, the diagnosis may be obvious from this history. In other cases, further testing is needed. The tests that are ordered vary, depending on the suspected cause. A cranial CT scan may be done if a brain tumor or stroke is suspected. A blood test can help diagnose temporal arteritis or diabetes.
Long-term effects depend on the cause. Presbyopia causes a permanent loss of vision in near objects. However, reading glasses or bifocals are the only treatment needed and there are no other long- term effects. A brain tumor can cause death. Glaucoma, macular degeneration, and diabetes can all result in permanent blindness or vision changes.
Vision changes themselves pose no risks to others unless the person engages in dangerous activities such as driving. If the cause of the vision change is an eye infection, such as conjunctivitis or keratitis, the infection may be contagious in some cases.
Treatment is directed at the cause. Medicines are often used to control diabetes or glaucoma. Retinal detachment, cataracts, some types of glaucoma, and brain tumors can be treated with surgery. Eye infections may need to be treated with antibiotics. Nearsightedness is usually treated with glasses or contact lenses.
Side effects depend on the treatments used. All medicines may have side effects. For example, those used to control diabetes may cause liver damage or allergic reactions. Surgery can be complicated by bleeding, infection, loss of vision, or reactions to anesthesia. Contact lenses may irritate the eyes or result in eye infections.
Treatment varies according to the cause of the vision change. After a person gets glasses, no further treatment may be needed aside from periodic checkups. People who have diabetes or glaucoma usually need close monitoring and treatment for life. Macular degeneration often causes vision to get worse over time, so treatment may change.
The eye care professional should be told about any changes in vision or the responses to treatments. Repeat eye exams are advised for many causes of vision changes. Children with a lazy eye may need close monitoring along with surgery, special glasses, or a patch over one eye.
Cecil Textbook of Medicine, 1996, Bennett et al.
Harrison's Principles of Internal Medicine, 1998, Fauci et al.