Vision changes that occur gradually over time or that seem to come
and go are usually less serious than changes that occur suddenly and persist.
Sudden changes that happen in only one eye are usually the most serious. Any
sudden loss of vision lasting for more than a few seconds is a serious symptom
that requires emergency medical treatment.
Vision changes that occur with eye problems can include:
Most of the focusing power in the eye occurs along the front surface, at the cornea (the clear 'window' in the front of the eyeball), or within the lens, which sits behind the cornea inside the eye. The ideal cornea has a symmetrically curved surface, like a basketball. Astigmatism is caused by a cornea or a lens that is not symmetrical, like a football.
The cornea is the transparent window in front of the colored part of the eye. It bends (refracts) light rays to focus the light onto the retina...
Double vision (diplopia).
Double vision can occur in one or both eyes. When double vision occurs in both
eyes, the cause is usually eyemisalignment. Double vision in one eye only is usually
caused by a cataract, a displaced lens, or uncorrected
Objects in the vision field, such as floaters, flashes or
sparkles, or curtains.
Floaters are small spots or specks that "float" across
your field of vision. Before a migraineheadache, flashes of light or zigzag
lines may occur with other symptoms. If you have had floaters before, or if
flashes of light are part of your diagnosed migraine headaches, these are
usually not serious. Sudden flashes of light, new floaters, or a dark curtain
or veil across part of your vision may indicate a serious problem.
Trouble adjusting vision when entering a dark
Trouble focusing on close or faraway
Dark spots in the center of your vision
Lines or edges that appear wavy.
These symptoms have a variety of causes, including:
Age-related changes. Distorted vision
(metamorphopsia) can occur in one or both eyes. The most common causes of
blurred vision are nearsightedness (myopia) in teens and "long-arm syndrome"
(presbyopia) in people of about age 40, when reading glasses often become