Topic Overview

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.

Gradual vision changes may include:

• Blurred vision.
• Vision loss.
• Loss of side (peripheral) vision.
• Severe sensitivity to light (photophobia).
• Halos of light around objects.
• Jerky or jumping vision (nystagmus).
• Double vision (diplopia). Double vision can occur in one or both eyes. When double vision occurs in both eyes, the cause is usually eye misalignment. Double vision in one eye only is usually caused by a cataract, a displaced lens, or uncorrected vision.
• 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 migraine headache, 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 room.
• Trouble focusing on close or faraway objects.
• Dark spots in the centre of your vision field.
• Lines or edges that appear wavy.

These symptoms have a variety of causes, including:

• Age-related changes. Distorted (blurred) vision can occur in one or both eyes. The most common causes are nearsightedness (myopia) in children and teens and presbyopia in people of about age 40, when reading glasses often become necessary.
• Problems with the structures of the eye.
• Problems in the brain.
• Problems in the blood vessels of the head, neck, and eye.

Vision problems in older adults

Some of the common vision problems that occur in older adults include:

• Cataracts.
• Glaucoma.
• Breakdown (degeneration) in parts of the eye, such as macular degeneration.
• Dry eye syndrome (keratoconjunctivitis sicca), which occurs when the tear glands do not produce enough tears, causing your eyes to feel itchy, scratchy, and irritated.