Common Causes of Blurred Vision—And What to Do About It

What you need to know about fuzzy, unfocused eyesight—and what it can mean for your health.

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Blurry, unclear, unfocused vision is the most common eyesight problem, and usually it isn't anything major to worry about it.

Blurriness could just be a sign that your glasses or contacts prescription needs updating. Every once in a while though, fuzzy vision signals something more serious.

Always investigate what's causing your blurry vision. Knowing the reason behind it can be the difference between experiencing the world in all its dimensions or not.

"Sight is such a valued sense, but there are still a lot of problems that fall through the cracks," said Rajiv Shah, MD, assistant professor of ophthalmology at Wake Forest Baptist Medical Center.

Here are some of the causes of blurry eyes and what to do about them.

01 of 16

You Need Prescription Glasses—or You Need a New Prescription

Nearsightedness (myopia), farsightedness (hyperopia), and astigmatism are refractive errors and are the most common causes of blurry vision, according to the National Eye Institute (NEI).

They happen when the curve of the eye gets in the way of light focusing directly on the retina. The retina processes light rays into signals the brain can read.

In addition to being widespread, refractive errors may also be the easiest to fix. In most cases, all you need is a prescription from an optometrist or ophthalmologist for glasses or contact lenses.

LASIK laser surgery can permanently change the shape of the cornea to correct the problem in some people.

02 of 16

You Need Reading Glasses

Presbyopia is also a refractive error but one that strikes most people after the age of 40. It means you have trouble focusing on things that are close up, like reading material.

If you find you need to hold magazines, books, and menus farther away from your face in order to read them, presbyopia could be causing your blurry vision.

As with other refractive errors, eyeglasses, contact lenses, and surgery can help you see better if you develop presbyopia. If you aren't farsighted or nearsighted and you don't have astigmatism, reading glasses from the drug store may be enough, said Dr. Shah.

However, you should still see a healthcare provider to screen for any potential eye disease.

If you do have one of those other refractive errors, think about switching to bifocals, trifocals, or progressive lenses.

03 of 16

You Caught Conjunctivitis

Conjunctivitis or pink eye is usually caused by adenoviruses, pesky viruses that can cause the common cold, bronchitis, and sore throats, according to the Centers for Disease Control and Prevention (CDC).

Although not usually serious, conjunctivitis can spread like wildfire in schools and other crowded venues.

"Virus particles on surfaces can stay alive for about two weeks," said Kim Le, MD, a pediatric ophthalmologist with the Henry Ford Health System in Detroit.

Conjunctivitis usually goes away in one to two weeks without treatment, but if you have severe symptoms, talk to your healthcare provider about antibiotics or antiviral medications.

In the meantime, try cool compresses to alleviate itchiness, warm compresses to relieve swelling, or over-the-counter eye drops to help with irritation, said Dr. Le.

Wash your sheets (especially your pillowcases) and your hands often to prevent the spread of germs.

04 of 16

You Sleep With Your Contacts In

If you don't use contact lenses properly, they can cause sight-robbing infections.

Contact lenses move across the eye every time you blink, creating micro-scratches on the surface of your eye. Infection-causing microorganisms can get caught under the lens and get into the scratches.

Sleeping with your contacts in, said Dr. Le, "is a perfect petri dish to grow those organisms and cause corneal ulcers," open sores on the cornea that can blur vision.

"Always, always take [contact lenses] out at night," added Dr. Shah, or toss disposable lenses at the end of the day.

05 of 16

You Have an Eye Infection

You don't have to wear contact lenses to get eye infections that damage the cornea.

Herpes keratitis is an infection in the eye caused by the herpes virus and is the most common cause of corneal infections, according to the CDC.

You can get it just by touching a cold sore on your lips then touching your eyes. Bacteria and fungi that muscle their way in after an eye injury can also cause infection.

Treatments like eye drops and medications (such as antibiotics, antivirals, and antifungals) usually help. But the best method of protection from eye infections is prevention.

Your cornea will do a lot of the preventative work for you. "The cornea is an amazing structure," said Bibiana Reiser, MD, assistant professor of ophthalmology at the Keck School of Medicine, University of Southern California and director of cornea and glaucoma services at Children's Hospital of Los Angeles.

"It has a lot of [antibodies] that kill things directly on contact."

06 of 16

You're Developing Cataracts

Cataracts are one of several eye problems that come with aging. According to the NEI, more than half of all people in the United States have cataracts by age 80.

This is when the lens in the front of the eye becomes cloudy and blocks light trying to reach the retina.

Cataracts usually take time to develop and don't cause any pain or other symptoms. Some stay small and cause few problems.

Those that do grow and interfere with vision are often treated with surgery to remove the aged lens and replace it with a clear lens implant.

"That is one of the most successful surgeries in all of medicine," said Dr. Shah.

07 of 16

You're Developing Glaucoma

Glaucoma is a group of eye diseases that cause vision loss and blindness by damaging the optic nerve in the back of the eye, according to the NEI. Like cataracts, glaucoma is usually slow to develop.

Glaucoma is known as the thief of sight, as it happens silently without any symptoms. And once the vision loss occurs, there's no way to bring it back.

"Patients with glaucoma don't even know it because the vision loss happens over decades," said Dr. Shah. "There's really no way to suspect it other than regular eye evaluations."

Once a diagnosis is made, prescription medications, laser treatment, and surgery can help.

08 of 16

You Have Age-Related Macular Degeneration

As you age, you have a higher risk of damage to the macula, an area near the center of the retina that helps you see details and objects directly in front of you.

Age-related macular degeneration, or AMD, is the leading cause of vision loss for older adults and results in a loss of central vision, per the NEI. This can make everyday activities like driving and reading understandably challenging.

There is no treatment for early AMD, although certain vitamins and minerals can slow the damage in intermediate AMD and people with late AMD in one eye, according to the NEI.

You can lower your risk for AMD by exercising, keeping your blood pressure and cholesterol at healthy levels, not smoking, and eating a lot of green, leafy veggies and fish.

09 of 16

You Have High Blood Sugar/Diabetes

High blood sugar can cause your vision to blur. "Really high sugars can lead to swelling of one's lens," said Dr. Shah. The swelling changes the shape of the eye and how it focuses, but the issue usually only lasts for a couple of hours or days.

If you suspect you might have high blood sugar, get checked right away. You're at a higher risk for type 2 diabetes if you have a family history of the disorder.

Besides blurry vision, other symptoms include:

  • Frequent urination
  • Excessive thirst
  • Unexplained weight loss
  • Excessive hunger
  • Yeast infections
  • Tingling and numbness in the hands and feet

If you have undiagnosed type 1 or type 2 diabetes, or diabetes that has been diagnosed but isn't well-managed, you're at risk for diabetic retinopathy.

This is when blood vessels in the back of the eye get damaged, and in later stages, leak and start bleeding into the eye. This results in seeing floating spots or streaks that look like spider webs, according to the NEI.

If you know there's a problem, injections and laser surgery can help save your vision, but "unfortunately, this is the sneak thief of vision," said Dr. Shah. "You can lose your vision from diabetes and not know you have diabetes."

Controlling your blood sugar can prevent diabetic retinopathy. If you have diabetes, make sure you get regular eye exams and see a healthcare provider for health checkups which will also check for diabetes.

10 of 16

You Have High Blood Pressure

You may already know that high blood pressure can lead to stroke and heart disease. What you may not know is that it can also cause a mini stroke of the eye called vein occlusion.

"These patients feel no pain," said Dr. Shah. "They will wake up and their vision is blurry." Blurry vision due to vein occlusion usually strikes just one eye, added Dr. Shah.

Treatments for vein occlusion, including medication to ease swelling of the macula, need to be given right away in order to be effective. Even then, you may lose some of your sight.

To protect against vein occlusion, if you're over 50 and have high blood pressure, Dr. Shah recommended getting regular eye exams.

11 of 16

You Get Ocular Migraines

An ocular migraine is typically caused by spasm of the blood vessels that feed the part of the brain responsible for processing vision, Vicente Diaz MD, MBA, a Yale Medicine ophthalmologist, told Health.

"Symptoms include flashing lights, blind spots, and seeing patterns often with many jagged edges and corners," explained Dr. Diaz.

According to the American Optometric Association (AOA), an ocular migraine can occur with or without a headache and typically will last under an hour.

Dr. Diaz added that the term "ocular migraine" can also refer to a retinal migraine, a rare condition that causes loss of vision in one eye only and can indicate problems with retinal blood flow.

12 of 16

You Have a Concussion

If, after banging your head pretty hard, you end up with vision issues, you might have a head injury.

"A concussion can lead to blurry vision, along with many other visual changes, such as double vision, difficulties with shifting gaze quickly from one point to another, problems focusing, and loss of binocular vision (eye alignment)," explained Barbara Horn, OD, past president of the American Optometric Association and president of Beach Eye Care & Audiology in Myrtle Beach, SC.

If you think you have a concussion, contact a healthcare provider immediately to be evaluated.

13 of 16

You're Stressed Out

Stress and anxiety can impact your health in many ways, including your vision. "Many patients are not aware of how stress can impact their vision and eye health," said Dr. Horn.

"Stress can cause the pupils to unnecessarily dilate and adrenaline can increase pressure on the eyes."

While the long-term impact of stress on the eyes can vary, most mild discomfort can be resolved by naturally lowering your stress level, explained Dr. Horn.

However, continuous heightened stress levels can cause permanent vision loss. In order to prevent stress-related vision problems.

Dr. Horn suggested maintaining a healthy lifestyle, taking visual breaks from screens and technology and adopting other stress-reducing activities, like meditation and exercise.

14 of 16

You Have a Rare Condition Called Uveitis

If your eye blurriness and dryness are accompanied by inflammation in or around the eye, you could have uveitis.

The inflammation usually happens when your body is fighting an infection or you have an autoimmune disease, according to the NEI. The most common causes of uveitis arecorneal abrasion/ eye trauma, infection, and autoimmune disease.

The prevalence of uveitis is pretty low, but the damage can be quite severe, said Dr. Diaz. Symptoms vary depending on what part of the eye is affected

"Inflammation in the front part of the eye presents with redness, light sensitivity, and pain, whereas inflammation in the back part of the eye presents with floaters, fuzzy vision, and flashing lights," explained Dr. Diaz.

According to the NEI, treatment for uveitis usually involves steroids given in some form, from pills and eye drops to injections and implants.

15 of 16

You Have Dry Eye Syndrome

According to Dr. Diaz, nearly 5 million people in the United States deal with dry eye syndrome. "The most common types of dry eye syndrome are insufficient tear production or excessively rapid tear evaporation," said Dr. Diaz.

The tear film is essential for comfort, the health of the eye, and for maintaining an optically clear surface. As light enters the eye, it first encounters the tear film and then the cornea, the most superficial and front part of the eye.

"If the tear film is unhealthy or lacking, then the cornea will become irritated and light will be scattered rather than focused as it enters the eye, leading to blurred vision," explained Dr. Diaz.

16 of 16

When Should You See a Healthcare Professional?

Fortunately, most of the reasons for blurry vision don't threaten your eyesight. But there are times when you should visit an emergency room or at contact a healthcare provider as soon as possible:

  • If your vision changes suddenly and doesn't get better after you blink your eyes
  • If you have pain in your eye
  • If you have no vision in a specific area
Updated by
Leah Groth

With decades of experience as a health, wellness, and fitness journalist, Leah Groth has one mission: To help you become the healthiest version of yourself. A Los Angeles native currently based in Philadelphia, her bylines appear in a number of magazines and websites, including Shape, Glamour, Forbes Health, Reader's Digest, Everyday Health, Byrdie, CBS News, and Verywell. When she isn't writing, she can be found exploring the east coast with her husband and two children. But most of the time, she is writing.

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