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JAMA Patient Page
August 8, 2017

Sudden Vision Loss

JAMA. 2017;318(6):584. doi:10.1001/jama.2017.7950

Vision loss is caused by problems at any point along the visual pathway from the eyes to the brain, and sudden vision loss is an emergency.

The process of vision involves light passing into the eye and being transformed into electrical signals that are processed in the brain. Light enters the eye through an opening called the pupil and is changed into electrical signals by cells located toward the back of the eye in the retina. These signals then travel from the eyes through the optic nerves to the brain. In the brain, the occipital lobes process the visual information to make sense of it. Problems at any point along this visual pathway can cause vision loss.

Signs and Symptoms

Sudden vision loss is vision loss that occurs over a period of a few seconds or minutes to a few days. Vision may become blurry or cloudy, completely absent, or affected by flashing lights or specks in the visual field called floaters. Part of the field of vision or the entire field of vision may be affected. It is helpful to cover one eye and then the other to determine whether one eye or both eyes are affected. Sudden vision loss is most often painless but may be associated with eye pain, redness, and headache. Any sudden change in vision is potentially serious, even if it involves only part of the visual field or resolves on its own.


Common causes of sudden vision loss include eye trauma, blockage of blood flow to or from the retina (retinal artery occlusion or retinal vein occlusion), and pulling of the retina away from its usual position at the back of the eye (retinal detachment). Inflammation of the blood vessels that supply the eye and the optic nerve or inflammation of the optic nerve itself can also cause vision loss. A sudden blockage of blood flow to the occipital lobe of the brain (as can occur with a stroke) is another common cause of sudden vision loss.


Sudden vision loss is a medical emergency, and anyone with sudden vision loss should seek medical attention quickly. Evaluation may include an eye examination and a neurological examination to test the function of the eyes and brain. Blood tests and brain imaging tests may also be ordered as part of the initial evaluation. The examination and tests are performed to look for specific eye problems as well as generalized medical conditions that may be related to the vision loss.


Vision loss due to problems with the eye may be treated with eye drops, medications, or surgery. If inflammation is the cause of the vision loss, steroids may be used. If the vision loss is caused by a sudden blockage of a blood vessel, treatment is directed at improving blood flow as soon as possible. Depending on the cause, vision loss can be minimized or reversed if treatment occurs quickly.

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The JAMA Patient Page is a public service of JAMA. The information and recommendations appearing on this page are appropriate in most instances, but they are not a substitute for medical diagnosis. For specific information concerning your personal medical condition, JAMA suggests that you consult your physician. This page may be photocopied noncommercially by physicians and other health care professionals to share with patients. To purchase bulk reprints, call 312/464-0776.
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Article Information

Sources: Merck Manual, National Library of Medicine, American Academy of Ophthalmology

Newman N, Biousse V. Diagnostic approach to vision loss. Continuum (Minneap Minn). 2014;20(4):785-815.

Bagheri N, Mehta S. Acute vision loss. Prim Care Clin Office Pract. 2015;42(3):347-361.

Topic: Ophthalmology