Sudden Blurry Vision in Both Eyes: Symptoms, Causes and Treatment

“Occasionally, eyedrops contain ingredients that can be irritating to the eye or may have some toxicity,” says Michelle Andreoli, MD, spokesperson for the American Academy of Ophthalmology and comprehensive ophthalmologist at Northwestern Medicine. “Typically, the irritating or toxic agents in an eyedrop are the preservatives. If an eyedrop causes blurriness or irritation, the best course of action is to not use the drop again and rinse the eye out with preservative-free over-the-counter artificial tears. This will typically remedy any discomfort or blurriness in two to three hours.”

If not, she adds, you should see your ophthalmologist.

Stroke or Transient Ischemic Attack (TIA)

When you have a stroke (a.k.a. a “brain attack”), part of your brain loses its blood supply, which keeps that area of the brain from getting oxygen. When the affected brain cells are starved of oxygen, they stop working properly and that can cause sudden vision loss.

A TIA, often incorrectly dubbed a “mini stroke,” is as serious as a true stroke and can also affect large areas of the brain. A big difference between the two? A stroke doesn’t stop on its own and requires treatment to stop and reverse the effects. With a TIA, the symptoms generally last less than an hour, but may continue up to 24 hours.

Retinal detachment

As the name suggests, retinal detachment happens when your retina (the light-sensitive layers of nerve tissue at the back of your eye) pulls away from its normal position. If a retinal detachment isn’t treated right away, more of the retina can detach, which increases the risk of permanent vision loss or blindness.

Diabetes-related retinopathy

People with diabetes — especially those who struggle to keep blood sugar levels in check — face a higher risk of diabetic retinopathy, the leading cause of blindness in adults. When elevated blood sugar levels remain high for long periods of time, the tiny blood vessels throughout the body, including those in the retina, are damaged. The result: retinal swelling and blurred vision, usually in both eyes. While diabetic retinopathy generally develops gradually, sudden vision loss can occur if a fragile blood vessel bleeds into the eye or a retinal detachment is triggered.

Wet age-related macular degeneration (AMD)

With AMD you lose your central vision, leaving you unable to see fine details of whatever it is you’re looking at. Say, for instance, you’re trying to read the time on a clock with hands from across the room or even up close. With AMD, you might see the clock’s numbers, but not the hands.

Of the two types of AMD — dry and wet — only the latter comes on quickly.  And although wet AMD is less common, it’s much more serious since you lose vision faster with wet AMD than with dry AMD.

Closed-angle glaucoma

With glaucoma, ocular fluid can’t drain as it should, and the pressure from that build-up in the eye damages the optic nerve, leading to partial vision loss or blindness. This happens suddenly with closed-angle glaucoma (a.k.a., angle-closure glaucoma or narrow-angle glaucoma), a rare form of the condition.

Complicating matters: Although some people experience early symptoms like halos, mild headaches, eye pain, or blurred vision, people at risk for closed-angle glaucoma usually show no symptoms at first. 

Is sudden blurred vision an emergency?

It can be. Obviously, the temporary cloudy vision caused by eye drops isn’t typically a medical emergency. But when blurred vision is accompanied by symptoms such as paralysis, dizziness, or trouble talking (all signs of a stroke) or a sudden increase in floaters, flashes of light, and a dark shadow on the sides or in the middle of your field of vision (symptoms of retinal detachment), it’s a medical emergency that requires immediate medical attention. Not sure? Play it safe. Call 911 or head to the emergency room right away.

“Sudden blurred vision is more of an indication of an acute condition in the body that needs to be urgently assessed,” says Abugo.

What are the treatment options for sudden cloudy vision in both eyes?

It depends on the cause. Blurry vision due to problems with the eye itself may be treated with eye drops, medications, or surgery. If inflammation is to blame, steroids may be used. And if there’s sudden blockage of a blood vessel, the goal is to improve blood flow as soon as possible.

“Treatment of blurred vision usually takes a systematic approach that looks at onset — for instance, gradual versus sudden — associated symptoms such as slurred speech or limb weakness, and medical history,” says Abugo. If the blurred vision came on suddenly, your doctor will generally treat the condition causing the sudden blurriness. “This is in contrast to a cataract, which typically is addressed non-urgently over a series of visits that may result in surgery by your ophthalmologist,” adds Abugo.

“If any change in vision is experienced, it’s important to see your ophthalmologist right away,” advises Brissette. “Prompt evaluation by a healthcare professional can help diagnose the underlying cause and prevent further damage, which is important to preserving your vision and health.”

What if you get blurry vision when you stand up?

You may have a type of low blood pressure called orthostatic hypotension, a condition in which your blood pressure quickly drops when you stand up after sitting or lying down. “Rapid onset blurriness when you stand is most commonly related to an abrupt decrease in blood supply to the head,” says Andreoli. “Blood pressure issues, medications, and dehydration can often cause this type of change.”

If it happens regularly, you should see an ophthalmologist. Symptoms usually improve when you change your medications or make a practice of standing up slowly.

Can dehydration cause blurry vision? 

Dehydration can also raise your risk for dry eye syndrome, one of the most common causes of blurry vision, and that in turn can up your chances of having blurred vision.

Can stress cause sudden blurry vision?

Stress is to blame for everything from chest pain and a weakened immune system to digestive woes, muscle aches, trouble sleeping—the list goes on. It is not, however, usually to blame for blurry vision. A rare exception: Ophthalmic migraines (a.k.a. ocular migraine and retinal migraine).

“Stress can lead to migraine issues in the brain, and this can cause an isolated visual event called ophthalmic migraine which is a loss of vision that lasts 15 to 30 minutes,” says Andreoli.

Ophthalmic migraines can affect vision in one or both eyes, adds Andreoli, though research suggests they more commonly affect just one eye.

What happens if you have blurry vision and nausea?

This odd combination of symptoms should be treated as a medical emergency. “Blurry vision that comes with pain in the eyes and nausea can be very dangerous and can represent a severe eye condition called acute angle closure glaucoma,” says Andreoli. “This can cause blindness very quickly. Any patient with blurry vision, pain, and nausea should immediately call their local ophthalmologist.”