When is sudden blurry vision an emergency?
A problem in any part of the eye can cause sudden blurry vision, but when present in only one eye, it may be a medical emergency. It should be evaluated and treated by a physician as soon as possible — to prevent permanent damage and vision loss.
Sudden blurry vision may be the body’s warning about a serious health problem. Prompt medical treatment can lead to the best possible outcome.
The following warning signs may be an indication of a serious eye problem. If you experience even one of these, seek emergency medical services immediately for evaluation and treatment:
- sudden unexplained change in your vision (e.g., blurred vision)
- eye pain
- eye injury
- signs of a stroke, such as a facial droop, one-sided weakness, or difficulty speaking
- marked vision impairment — especially if only in one eye
- loss of one aspect of the visual field
- sudden blurred vision secondary to a weakened immune system due to conditions like HIV or chemotherapy treatment
Can a stroke affect your vision?
Yes, a stroke can affect your vision. According to the American Stroke Association, about 65% of stroke survivors have vision problems.
There are four main vision deficits from stroke. These include:
- visual field loss
- eye movement problems, where damage to the nerves and muscles of the eye affect focus and movement
- visual processing problems, where awareness of one side of the body is inhibited
- other post-stroke vision impairments, including blurry vision, double vision, vision loss, and light sensitivity
How vision is affected by a stroke depends on multiple factors including:
- severity of the stroke
- length of time elapsed before treatment
- what part of the brain was affected by the stroke
The specific location of the stroke determines the type of vision loss. Damage to the right side of the brain causes changes in the left eye, while damage to the left side of the brain causes vision changes in the right eye.
The most common stroke-related vision problems include:
Visual field cut
The visual field is everything that you can see including straight ahead (central vision) and on the side (peripheral vision).
A visual field cut (visual field loss) is a partial loss of vision. Strokes visual field deficits include:
- Homonymous hemianopia: peripheral vision loss that occurs in either the right or left half of the field of vision.
- Homonymous quadrantanopia: vision loss that occurs in either the upper or lower quarters of the visual field.
- Scotoma: a blind spot occurring anywhere in the visual field.
Sudden blurry vision
Is blurred vision in one eye a sign of stroke? Yes, a stroke can cause sudden blurry vision in one or both eyes if it affects an area of the brain that controls sight. A transient ischemic attack (TIA) — a ministroke — can also cause blurry vision.
Double vision (diplopia)
When the eye muscles are weakened after a stroke, the eyes are unable to align with each other, giving a visual perception of two objects — diplopia. Double vision after a stroke can be present all the time or present only when looking in a certain direction.
Diplopia can cause blurry vision, rather than distinct double vision — the two images may overlap, appearing blurred.
Spatial inattention/visual neglect
Spatial inattention is when a person doesn’t respond to and isn’t aware of things on their stroke-affected side. This problem isn’t related to actual sight but results from damage to parts of the brain that perceive and interpret vision.
Eye movement disorders
Eye movement disorders can occur when the nerves and muscles that allow eye movement are damaged due to stroke. Examples of this include:
- rapid eye jiggling (nystagmus)
- eye turning (strabismus)
- eye tracking control issues (oculomotor dysfunction)
- double vision (diplopia)
Depth perception, balance, coordination, and overall vision can be affected by all of these.
Dry eye and light sensitivity
Some stroke survivors have problems with blinking or not being able to fully close their eyes. When this happens, the eyes lose their natural moisture and become dry, causing irritation, burning, blurry vision, and light sensitivity.
Loss of vision
A stroke can cause complete loss of vision in one eye — rarely, in both eyes. Complete loss of vision in one eye is due to a blockage in either a retinal artery.
If you experience any of these warning signs with other stroke symptoms like sudden weakness or numbness on one side of the body, an intense headache, and/or difficulty speaking or walking, seek emergency medical services.
What are the different types of strokes?
Strokes are responsible for 1 out of every 20 adult deaths in the US. Prompt and appropriate treatment for a stroke is critical to prevent the death of brain cells and loss of capacity.
A stroke occurs when the brain is deprived of oxygenated blood due to a blood vessel occlusion or rupture. The different types of strokes include:
Ischemic stroke
An Ischemic stroke occurs when blood clots or fatty deposits block blood vessels in a certain part of the brain, depriving it of oxygenated blood. Most strokes are ischemic strokes.
Hemorrhagic stroke
A hemorrhagic stroke happens when an artery in the brain leaks blood or ruptures. High blood pressure and aneurysms are examples of conditions that can cause a hemorrhagic stroke.
Transient ischemic attacks (TIA or “ministrokes”)
A transient ischemic attack is a warning sign of a future stroke and is a medical emergency, just like a major stroke. More than one-third of people who have a TIA but don’t get treatment have a major stroke within one year.
Vision issues occur more often in people with stroke risk factors like hypertension, diabetes, atrial fibrillation, and carotid artery disease.
What visual processing areas of the brain are affected by a stroke?
The visual processing areas of the brain affected by stroke include:
- The occipital lobe: The occipital lobe is the main vision center of the brain. While all areas of the brain are involved in processing visual information, this is where most of it occurs.
- The brain stem: The brain stem is located at the base of the brain. This area controls eye movements, balance and stability, and the ability to recognize objects.
How is vision loss diagnosed after a stroke?
A doctor or other healthcare professional will refer you to an eyecare specialist to help with a diagnosis of post-stroke visual problems.
The type of eye doctor (or doctors) will depend on the root cause of the problem:
- Ophthalmologists and optometrists are doctors who treat eye disorders.
- Neurologists treat conditions associated with stroke, brain injuries, and brain disorders. They focus on changes in the brain due to stroke and its impact on vision.
- Neuro-ophthalmologists and neuro-optometrists are specialties concerned with visual symptoms resulting from changes in the brain.
Can vision improve after a stroke?
Most people with loss of visual function after a stroke will not fully recover their vision. Some recovery may be possible in the first few months. Glasses or contact lenses will not correct vision loss due to stroke.
Research from the University of Rochester found that stroke patients may retain some visual capabilities immediately after the stroke, but these abilities diminish and disappear permanently after six months.
Early vision training interventions are the key to recovering vision loss, rather than delayed interventions after six months. Treatment options include scanning techniques, the use of prism lenses, eye patches, eye drops, and sunglasses.
Vision loss can affect a stroke survivor’s safety and independence. Training and other modifications may be able to limit the loss.
Our expert staff at Assil Gaur Eye Institute can provide valuable information to you about what to do in an emergency if you suspect a stroke — before it happens. When you experience blurry vision, we can also ease any concerns by ruling out a dangerous medical condition.
Experiencing blurry vision? Assil Gaur Eye Institute of Los Angeles has your back!
Los Angeles’ leading LASIK, cataract, and retinal surgeons are available to you, all in one practice. State-of-the-art treatments for all eye conditions including glaucoma, macular disease, dry eye, and diabetic eye conditions, to name just a few.
Assil Gaur Eye Institute remains laser-focused on our founding mission of providing exceptional health care in a compassionate and caring environment. We continue to be driven to advance the field of ophthalmology and give back to our community every day.
Please call (866) 945-2745 or make an appointment online.
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She received her Doctorate degree in Optometry at the age of 23 and during her graduate training, Dr. Z also served as a research associate. Her research was presented at the Association for Research in Vision and Ophthalmology in 2012.
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