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  • Writer's pictureAtanas Bogoev M.D. and Maria Cholakova

When is Blurry Vision a Medical Emergency? Eye Doctor Explains

People are genuinely dependent on their eyes. That is also the reason why anxiety set in whenever we experience symptoms that compromise or severely affect our eyesight. Like most health conditions, blurry vision could be a serious emergency that requires urgent medical care at the emergency room. However, occasionally, a sudden vision blur does not warrant medical attention and it can be treated at home instead. So there is no need to panic right away.


Many eye conditions could cause blurred vision. Some of which are more severe than others. The condition could occur suddenly or evolve gradually over a long period of time. In light of the fact that dim or foggy eyesight is linked to some serious health issues, understanding when blurry vision would prompt a trip to the emergency room is crucial.


Keep on reading to learn if blurred vision is a medical emergency, what could cause sudden poor eyesight, and when is it time to seek professional medical care and assessment.


Table of Content:

1.2. Eye strain

1.4. Glaucoma

1.5. Cataracts


What are the possible causes of blurred vision?


Blurry vision is usually caused by a number of reasons. And as such the symptoms come in handy in identifying these reasons. So in order to investigate why the blur occurs, let's look at some of the probable causes:


Refractive errors

Onset: gradual within months or years


Refractive errors occur when the eye shape does not bend light properly, leading to blurry vision. Common types of refractive errors include nearsightedness (myopia), farsightedness (hyperopia), and astigmatism.


You can correct refractive errors with eyeglasses, contact lenses, or refractive surgery. Early detection and treatment of these errors could prevent vision problems from getting worse.


Blurry vision

Eye strain

Onset: gradual within hours, especially after intense work up close


Spending long hours staring at digital screens or reading in poor lighting conditions can cause eye strain. It is typically accompanied by a headache, located around the orbits.


Digital eye strain, also called computer vision syndrome, is one of the common causes of temporary blurry vision. This is not a dangerous eye condition and your sight should improve with adequate rest and regular screen breaks.


Physical trauma

Onset: sudden after trauma


Blunt force trauma to the eye, for example, can cause a variety of injuries such as corneal abrasions (small wounds of the corneal surface), hyphema (bleeding in the eye), vitreous hemorrhage (bleeding in the vitreous gel inside the eye), or retinal detachment. All of which can lead to vision blur.


Head trauma, such as a concussion, can also cause blurry vision, along with other symptoms like headaches, dizziness, and confusion.

It's critical to seek medical attention if you experience physical trauma to the eye or head.

The prompt treatment potentially prevents complications and minimizes the risk of long-term vision problems.


Glaucoma

Onset: gradual and progressive within months


Glaucoma is a condition in which the pressure inside the eye is too high and damages the optic nerve, leading to vision loss. The cause is a buildup of fluid in the eye, which puts pressure on the optic nerve.


In most cases, it is due to genetic factors and progresses with aging. There is no cure. However, early diagnosis and treatment can prevent or slow the progression of vision loss. Treatment usually starts with eyedrops or a laser that reduces intraocular pressure.


Onset: sudden with pain


In the case of acute angle closure glaucoma, the eye pressure increases suddenly. Leading to corneal edema and one can experience a sudden onset of severe blurry vision of one eye, accompanied by eye pain, headache, colorful rings or halos around bright lights, nausea, and vomiting.


Cataracts

Onset: gradual and progressive within months


Cataracts are a clouding of the eye's natural lens that may cause blurred or hazy vision. Cataracts are a common condition. They can develop as a result of aging, trauma, other diseases in the body such as diabetes, or exposure to some types of radiation.


Surgery is the only way to treat cataracts, and it is usually successful in restoring clear vision.


Macular degeneration

Onset: gradual and progressive within months


Macular degeneration is a condition that causes the retina center (the macula) to deteriorate, leading to distortion of vision. It is most common in individuals over the age of 60 and is the leading cause of vision loss in the elderly.


It is a natural process, so there is no cure for macular degeneration. Yet, prescription glasses and treatments such as nutritional supplements, laser therapy, and anti-VEGF injections (special factors that reduce the proliferation of new vessels in the retina) can slow its progression.


Onset: within weeks


In the cases of wet macular degeneration, new blood vessels can cause fluid buildup in the center of the retina (the macula). That may lead to blurry vision, accompanied by new distortions when looking at objects.


Old person with macular degeneration has blurry vision

Diabetic retinopathy

Onset: gradual within years


Diabetic retinopathy leads to vision loss or blurry vision due to damage to the blood vessels in the retina from the high glucose (sugar) blood levels. Early detection is the most effective way to prevent complications.


Patients with diabetes should have regular eye exams to check for signs of diabetic retinopathy with visits to their eye doctor at least once per year. Even if diabetic retinopathy is not present! Treatment can slow the disease progression and preserve vision.


Onset: sudden within days


Sometimes diabetic retinopathy affects the central part of the retina (the macula) and causes the so-called diabetic macular edema. In that case, the patient notices progressive worsening of vision over days, the objects look distorted, wavy, and smaller or larger than usual.


If you are a diabetic and experience similar symptoms, we advise that you get an urgent diabetic eye exam with an ophthalmologist.


Retinal detachment

Onset: sudden within hours or days


Retinal detachment may start with new onset of flashes, and floaters (new black floating dots) in your field of vision. Then progress to black shadows (some patients usually describe gray or black curtain in their periphery visual field). And eventually completely blurry vision.


Retinal detachments are more likely to happen to people who have nearsightedness (myopia). If dealt with early on when the central retina is still attached, the visual prognosis is good.


On the other hand, chronic retinal detachments or retinal detachments with a detached macula (the central part of the retina) have a poor visual prognosis, despite surgical treatment.


Optic neuritis

Onset: sudden within hours or days


Optic neuritis is an inflammation of the optic nerve that results in bad vision, eye pain, and often color vision loss. A common cause of optic neuritis is an infection or an autoimmune disorder.


Treatment may involve anti-inflammatory medications or steroids. It often restores vision, but it may take several weeks or months for a full recovery.


Migraines

Onset: sudden within minutes


Migraines can cause temporary vision disturbances, including blurry vision. They can also cause nausea, vomiting, and extreme sensitivity to light and sound. Some people experience "aura" before migraine onset. Which is characterized by flashing lights, blind spots, and tingling sensations.

Young woman with migraines and blurry vision

Neurological conditions

Onset: sudden within hours or days


Neurological conditions that affect the visual pathways in the brain can be a cause of blurred vision. Examples include multiple sclerosis and a stroke. Brain tumors, brain compressions, and other brain-related diseases can also cause vision problems, resulting in blurry vision.


Medications

Onset: variable from within hours to within months


Some medications, such as antihistamines, antidepressants, and certain blood pressure medications, can cause blurry vision as a side effect. Furthermore, some treatments can increase or decrease pupil size, temporarily blurring vision. And others can cause dry eyes, which can lead to blurriness, too.


When to Go to the Emergency Room for Blurry Vision?


Blurry vision can be a sign of a serious underlying condition that requires immediate medical attention. Consider going to the emergency room if you experience any of the following symptoms, along with blurred vision:

  • Sudden onset of vision loss in one or both eyes

  • Double vision

  • Severe eye pain

  • New onset of flashes or black points

  • Headache accompanied by vision changes

  • Weakness or numbness on one side of the body

  • Difficulty speaking or understanding speech

  • Loss of consciousness

These symptoms may indicate a stroke, retinal detachment, or other serious conditions that require urgent medical attention. Reacting fast is extremely important.


If you generally feel unwell, while having blurry vision, go visit your doctor as soon as possible to determine the possible cause and means of treatment. They will refer you to a specialist if needed.


Can Blurry Vision be Harmless?


Blurred vision can sometimes be a harmless symptom that resolves on its own without treatment. For example, if you have been reading in poor lighting conditions or staring at a digital screen for a long time, you may experience temporary blurred vision that goes away once you rest your eyes.


Similarly, if you have a refractive error and have not worn your glasses or contacts, you may experience blurry vision that you could correct with the proper prescription.


However, it is important to note that blurred vision can also be a symptom of a serious underlying condition. Therefore, if you experience blurry vision that persists or worsens over time, you should consult an eye doctor to rule out any potential eye or neurological problems.


When Does Blurred Vision Go Away?

Mountain view, half of picture is clear the other half imitates blurry vision

The duration of a blurry vision episode depends on the underlying cause. If the cause is eye strain, it may go away on its own once you rest your eyes and avoid digital screens or reading in poor lighting conditions. If your blurry vision is caused by a refractive error, it is easy to correct with prescription glasses or contact lenses.


However, if blurry vision is a result of a serious underlying condition, such as a stroke or retinal detachment, it may not go away on its own and requires immediate medical attention. The treatment and recovery time for these conditions vary depending on the severity and type of condition.


In general, if you experience blurriness that persists or worsens over time, you should consult an eye doctor. A medical professional is the only one who can determine the underlying cause and provide appropriate treatment options after a comprehensive eye exam.


Resources:

All medical facts checked by Atanas Bogoev M.D.

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