• Alternative names
• Definition
• Causes, Incidence and Risk Factors

• Prevention
• Symptoms
• Signs & Tests
• Treatment

• Expectations
• Complications
• Calling Your health care provider

Alternative Names

Blindness, temporary; diminished eyesight; decreased vision; eyesight diminished; impaired vision

Definition

Blurred vision is the loss of visual acuity or sharpness resulting in unclear visual details. Vision loss is the inability to perceive visual stimuli. See also blindness. Blind spots are apparent dark "holes" in the visual field in which nothing can be seen. An enlarging blind spot is growth in the size of a blind spot that is readily apparent to the individual.

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 doctor of optometry that specializes in evaluating the need for glasses and deciding on what prescription lens will provide the best vision. An optometrist can diagnose and treat many vision problems, although in some states, they can also diagnose and treat other medical problems.
• An ophthalmologist is a physician that specializes in eye disorders and is the appropriate person to consult for diseases of the eye.
• Sometimes an eye problem is part of a general health problem; in these situations, a primary care provider may be appropriate.
  

Causes, Incidence and Risk Factors

Common causes

• aging, (the most common cause of decreased vision)
• cataracts (also common in the elderly)
• glaucoma
• complications of diabetes
  • 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

Note: There may be other causes of vision abnormalities. This list is not all inclusive, and the causes are not presented in order of likelihood. The causes of this symptom can include unlikely diseases and medications. Furthermore, the causes may vary based on age and gender of the affected person, as well as on the specific characteristics of the symptom such as quality, time course, aggravating factors, relieving factors, and associated complaints. Use the Symptom Analysis option to explore the possible explanations for vision abnormalities, occurring alone or in combination with other problems.

Prevention

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.

Symptoms

• 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
  

Signs & Tests

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?

The physical examination will include an eye examination. The health care provider will check vision, eye movements, pupils, back of the eye, and eye pressure when indicated. An overall medical evaluation will be done if indicated.

Diagnostic tests that may be performed include:

• slit-lamp examination
• refraction test
• tonometry

Intervention: Surgery will be recommended for some conditions (such as cataracts or muscle problems). Diabetics must control their blood-sugar level. Other treatments depend on the cause.