A number of medical conditions can cause blurred vision that gradually worsens over days, weeks, or months. While these are worth addressing with your medical team, they don’t typically require emergency care.
“Gradual blurry vision is often related to chronic or progressive eye conditions that are treatable, but delaying care can still lead to preventable vision loss,” says Jacqueline M. Bowen, a doctor of optometry and the president of the American Optometric Association (AOA), who treats patients in Greeley, Colorado.
1. Refractive Errors
Refractive errors happen when differences in the shape of your eye bend light in a way that makes vision blurry.
“It is the most common cause of blurry vision and is corrected by glasses and contacts,” says Amy Walsh, MD, a board-certified emergency physician at HealthPartners in Amery, Wisconsin.
2. Eyestrain
You may experience eyestrain after staring at your computer all day or during a long drive. This common issue occurs when your eyes have to work harder than usual due to factors such as glare, reflections, and a lower blink rate. Along with blurry vision, you might also experience headaches, eye irritation, and neck and shoulder pain, Dr. Bowen says.
Take a 20-second break every 20 minutes to look at something at least 20 feet away, she suggests, to relax your eye muscles and reduce strain.
You can also try positioning your computer monitor so it’s at eye level and adjusting the contrast and brightness settings to enhance visibility and lessen eyestrain.
3. Dry Eye Syndrome
When your eyes don’t produce regular or enough lubrication, you may get blurry vision, Bowen says. This can happen to anyone, but it’s more common if you’re 50 or older, wear contact lenses, or have an underlying health condition that affects your tear production. You might also experience stinging, burning, sensitivity to light, or feeling like something’s in your eye. “Treatment may include lubricants, prescription eye drops, specialty contact lenses, and in-office treatments that help restore tear film stability,” she says.
4. Glaucoma
“Glaucoma is a sight-threatening disease that damages the optic nerve, usually from elevated eye pressure,” Bowen says.
There are two types of glaucoma: one that progresses gradually and another that comes on suddenly (more on that below). “In the gradual type, called open-angle glaucoma, vision will start to blur at the edge of the visual field, then progress toward the center as it worsens,” Dr. Walsh says. Most of the time, open-angle glaucoma worsens so slowly that people don’t notice any symptoms until later stages of the disease. It’s typically treated with eye drops, laser treatment, or surgery to reduce eye pressure, Bowen says.
5. Cataracts
“Cataracts cloud the eye’s natural lens, scattering light and reducing clarity,” Bowen says. More common after 40, you may also experience double vision, light sensitivity, and trouble seeing well at night. Cataract treatment involves surgically removing the cloudy lens and replacing it with a clear artificial lens, she says.
6. Medication Side Effects
These medications can alter your ability to focus your eyes, your tear production, or your eye pressure in ways that can lead to blurred vision, Bowen says.
Always talk to a healthcare provider before stopping a medication. “Treatment involves adjusting the medication with the prescribing provider or managing symptoms with targeted eye care therapies,” she says.
7. Age-Related Macular Degeneration
Common after 50, age-related macular degeneration involves damage to the macula, a part of the eye that sharpens your central vision.
This type of vision loss makes the middle of your field of vision blurry and details harder to see, while your peripheral vision remains clear, Bowen says. “Treatment may include use of visual aids, medication injections, and specific light therapy techniques,” she adds.
8. Diabetic Retinopathy
In people with diabetes, high blood sugar can damage blood vessels in the eyes, leading to distorted vision. Alongside blurriness, you may also see blank or dark areas or notice colors seem washed out or faded.
Your eye doctor will work with your endocrinologist to help you monitor and manage your diabetes and associated eye problems, Bowen says. Depending on the severity, you may need laser therapy, injections, or surgery to treat your vision.