Alternate Names: Blindness - temporary; Diminished eyesight; Decreased vision; Eyesight diminished; Impaired vision

Considerations: Loss of visual acuity, changes in vision, blurriness or decreased light perception should always be evaluated as soon as possible by a medical profesional. Changes may represent primary eye disease, aging, eye trauma, or a generalized (systemic) illness. Whatever the cause, visual changes should never be ignored. Decreased vision is a significant threat to the quality of life. Professional help is always indicated, but which professional to see is often a question.

Here are some tips:

• An optician dispenses glasses and does not diagnose eye problems.
• An optometrist is a state-licensed health care professional who diagnosesand treats eye health and vision problems. They prescribe eyeglasses and contact lenses, low vision aids, and vision therapy and medicines to treat eye diseases, as well as perform certain surgical procedures.
• An ophthalmologist is a physician -- a medical doctor (MD) or doctor of osteopathy (DO) whospecializes inthe medical and surgical treatment of eye diseases or otherconditions. They may also provide routine vision care services such as prescribing eyeglasses and contact lenses.
• Sometimes an eye problem is part of a general health problem; in these situations, a primary care provider may be appropriate.

Common Causes:

• aging, (the most common cause of decreased vision)
• cataracts (also common in the elderly)
• glaucoma
• complications of diabetes (the most common cause of blindness in the United States)
  • intermittent or fixed double vision (usually temporary)
  • retinal hemorrhages, which can cause more permanent blindness
  • diabetic retinopathy
• eye infection, inflammation, or injury
  • infections of the cornea that cause scarring, distortion or perforation
  • infections of the retina with viruses, fungi or parasites--seen with increasing frequency in AIDS.
• floaters (tiny particles) drifting across the eye
  • usually are harmless and require no treatment
• fatigue and prolonged exposure to the outdoors (temporary and reversible blurring of vision)
• drugs (blurring, spots, and halos)
  • anticholinergics
  • antihistamines
  • clomiphene
  • chloroquine
  • cycloplegic
  • digitalis derivatives (temporary)
  • ethambutol
  • guanethidine
  • indomethacin
  • methanol toxicity (permanent)
  • phenothiazines
  • phenylbutazone
  • quinine sulfate
  • reserpine
  • thiazide diuretics
• migraine headaches (spots of light, halos, or zigzag patterns are common preliminary symptoms)
• congenital disorders
• heritable disorders

Home Care: Safety measures may be necessary to help a person with vision abnormalities. For example, it may be helpful to increase the amount of light in a room.

Call If:

• any sudden visual changes occur
• there is partial or complete blindness in one or both eyes
• there is trouble seeing objects to either side (decreased peripheral vision) or if halos are seen around lights.
• blind spots suddenly appear

• For decreased vision in a child, see an optometrist or an ophthalmologist.
• For sudden blindness in one eye in an elderly person, see an ophthalmologist or an internist immediately.
• For eye pain or halos around lights, see an ophthalmologist.
• For gradual loss of visual acuity in an adult who wears glasses, see an ophthalmologist or optometrist.
• For sudden blindness in both eyes in a healthy young person, see an internist or ophthalmologist immediately.
• For gradual blurring of vision in an older person, not helped by moving closer or farther away, see an ophthalmologist.
• For an older person who sees far objects best and near objects not very well, see an optometrist or ophthalmologist.
• For visual changes that occur while taking medication, see the prescribing doctor.
• For decreased vision in one eye with a "shadow" in the visual field, see an ophthalmologist immediately.

What To Expect: The medical history will be obtained and a physical examination performed.

Medical history questions documenting the vision abnormalities in detail may include:

• time pattern
  • When did this begin?
  • Did it occur suddenly or gradually?
  • Does it occur only occasionally? How often?
  • How long does it last?
  • When does it occur? Evening? Morning?
• quality
  • Is the vision blurred or is there double vision?
  • Are there blind spots?
  • Are there areas that look black and missing?
  • Is side vision missing?
  • Are halos (circles of light) seen around shiny objects or lights?
  • Are flashing lights or zigzag lines seen?
  • Is extreme sensitivity to light present?
  • Do stationary things seem to be moving?
  • Are colors missing?
  • Is it difficult to differentiate colors?
  • Is there pain?
  • Is there drainage from the eye(s)?
  • Are the eyes crossed?
  • Does one of the eyes "drift"? Do both?
• location
  • Is the problem in one eye or both eyes?
• aggravating factors
  • Have you had any of the following in the last few weeks to months?
    • injury
    • infection
    • increased stress
    • anxiety
    • depression
    • fatigue
    • headache
    • exposure to pollens, wind, sunlight, or chemicals
    • use of soaps, lotions, or cosmetics
• relieving factors
  • Is your vision better after you rest?
  • Is it better with corrective lenses?
• other
  • What other symptoms are also present?
    • redness
    • swelling
    • bruising
    • headache
    • pain
    • itching
    • a sense that something is in the eye
    • increased tearing
    • decreased tearing
• additional important information
  • What medications are being taken?
  • Is there a family history of diabetes?
  • Have you had a previous head injury?
  • Do you have any allergies?
  • Has there been a loss of eyelashes?

• slit-lamp examination
• refraction test
• tonometry