What causes sudden blurry vision?
If you are experiencing sudden blurry vision in one or both eyes, and find yourself blinking, rubbing your eyes or squinting to see better, you might blame age or a worsening eye prescription.
However, certain medical conditions as well as dehydration and eye strain can cause sudden blurry vision. The causes for steadily increasing blurred vision differ from sudden onset blurry vision. Sudden blurry vision should be checked out immediately by an eye doctor to determine if other health issues are the cause.
Sudden blurry vision vs. progressive blurry vision
Long-term medical conditions are usually related to progressively increased blurry vision while sudden blurry vision happens after a single event. Sudden blurry vision is usually a medical emergency that should be treated as soon as possible to prevent vision loss and permanent damage.
Common causes of sudden blurry vision
Sudden blurry vision is typically caused by a one-time event like a retinal detachment or injury. In addition to sudden blurry vision, these can also trigger other vision-related symptoms, including double vision (diplopia) or light sensitivity (photophobia). If you’re experiencing sudden blurry vision, one of the following common conditions may be the culprit:
Eye strain is a frequent reason for sudden blurry vision, especially considering how much time is spent staring at screens and electronic devices.
Corneal abrasion, or a scratched cornea, is fairly common and can occur when any foreign substance (sand, dust, makeup, etc.) makes contact with or gets into your eye — fortunately, this condition typically heals on its own in a few days.
A visual migraine (also called a migraine aura) is a headache that may include temporary blurred vision. A visual migraine can occur suddenly and move across your field of view and disappear within 30 minutes. If you experience any blind spots, consult an eye doctor immediately to determine if an underlying condition is happening, such as a retinal detachment.
Detached retina occurs when the light-sensitive retina separates from the back of the eye. If not treated, this condition can continue to worsen and lead to irreversible vision loss.
SEE RELATED Blurred vision after eye surgery.
Serious conditions that can cause sudden blurry vision
In most cases, sudden blurry vision is not caused by serious medical conditions. However, there are rare cases in which a systemic health condition can cause vision-threatening complications, including sudden blurry vision.
If you experience any of the following, seek immediate medical attention.
A stroke can cause abrupt, painless changes in eyesight, including sudden blurry vision. Other signs to look for include dizziness, loss of balance, slurred speech, weakness or numbness in one arm, eye twitching, and face dropping.
A transient ischemic attack (TIA) is the same as a stroke, except that symptoms last for a short period of time. TIAs serve as warning signs of an impending stroke.
Diabetes: You may experience sudden blurry vision or patches of missing sight without even noticing it. Annual comprehensive eye exams will catch this condition early before damage occurs.
Optic neuritis is an inflammation of the optic nerve that causes blurred, grey or dim vision and often affects only one eye. When the optic nerve is inflamed, it damages the protective sheath (myelin) that surrounds the nerve. Some vision symptoms of this condition are blind spots, blurry vision, loss of vision and distorted vision. This condition is usually an autoimmune reaction or a sign of multiple sclerosis.
Wet macular degeneration is caused by leaky blood vessels in the retina. Early symptoms include unusually fuzzy or distorted vision. There are laser treatments that may slow vision loss but can’t restore your vision.
Conjunctivitis (also called pink eye) usually goes away on its own, but antibiotics or antiviral medication can often speed recovery and lower the chance it will spread.
Treatment of sudden blurry vision
To determine proper treatment for sudden blurry vision, you need to understand the cause. For example, if you know that your body is dehydrated and needs water and rest, you can simply drink plenty of water to rehydrate your eyes and relieve them from dry eye and irritation.
Similarly, a good solution for sudden blurry vision due to eye strain is simply resting the eyes. Try the 20-20-20 rule: Focus on an object 20-feet away for 20 seconds every 20 minutes. Blinking is also important because it moistens your eyes to prevent dryness and irritation.
Other causes of sudden blurry vision may require medical intervention. If you have cataracts, for instance, your eye doctor may recommend an outpatient procedure during which the lens will be replaced, resolving the sudden blurry vision issue.
A more serious condition like a detached retina may also require surgery. You should always talk to an eye doctor to determine the cause of your sudden blurry vision before attempting to treat your sudden blurred vision.
When to see an eye doctor
If you experience a sudden change in your vision, eye pain, reduced vision in one eye or any symptoms from the serious conditions list, contact your eye doctor or go to the emergency room immediately. Never assume the cause or attempt to treat your condition without consulting a medical expert.
Questions that your doctor may ask include: How long have you had sudden blurred vision? Are there other symptoms associated with your sudden blurry vision? Have any injuries occurred to the eye area or otherwise? Are you currently taking any medications?
Once the cause for your sudden blurry vision is diagnosed, follow your eye doctor’s treatment plan to reduce the risk of vision issues down the road.
Page published in January 2021
Page updated in April 2022