Blurry Vision
Causes, Symptoms, and When to Seek Eye Care
Blurry vision is one of the most common reasons people visit an eye doctor. It can affect one eye or both eyes, develop gradually over time, or occur suddenly without warning. Sometimes blurry vision is caused by something simple, such as needing a new glasses prescription or having dry eyes. In other cases, it may be an early sign of cataracts, glaucoma, diabetic eye disease, macular degeneration, retinal problems, or even a medical emergency such as a stroke or retinal detachment.
Because blurry vision has many possible causes, a comprehensive eye examination is the best way to determine why your vision has changed and what treatment is appropriate.
What Does Blurry Vision Feel Like?
Patients describe blurry vision in many different ways, including:
- Difficulty seeing objects clearly
- Vision that appears out of focus
- Trouble reading small print
- Difficulty recognizing faces
- Blurry vision while driving
- Trouble seeing road signs
- Difficulty focusing when switching between near and far objects
- Vision that seems hazy or smeared
- Blurred vision that comes and goes
- One eye seeing more clearly than the other
Some people notice blurry vision only at certain times of the day, while others experience constant blurred vision that gradually worsens.
Common Causes of Blurry Vision
Refractive Errors
The most common cause of blurry vision is an uncorrected need for glasses or contact lenses.
This includes:
- Nearsightedness (myopia)®
- Farsightedness (hyperopia) ®
- Astigmatism®
- Presbyopia (difficulty reading after age 40) ®
Fortunately, these conditions are usually corrected with glasses, contact lenses, or vision correction procedures such as LASIK.
Dry Eye Disease
A poor-quality tear film is one of the most overlooked causes of blurry vision.
Vision may:
- Fluctuate throughout the day
- Improve after blinking
- Become worse while using computers
- Feel gritty or irritated
- Improve temporarily with artificial tears
Dry eye commonly causes intermittent blurry vision rather than constant blur.
Cataracts
Cataracts cause the eye's natural lens to become cloudy, leading to:
- Gradually worsening blurry vision
- Difficulty driving at night
- Increased glare
- Halos around lights
- Faded colors
- Frequent glasses prescription changes
Cataracts are one of the most common causes of blurry vision in adults over age 60.
Macular Degeneration
Age-related macular degeneration (AMD) affects the center of the retina (macula), leading to:
- Difficulty reading
- Blurred central vision
- Distorted vision
- Missing spots in vision
- Difficulty recognizing faces
Early diagnosis is important because some forms of AMD can be treated to preserve vision.
Diabetic Eye Disease
Diabetes can damage the small blood vessels inside the retina.
Blurry vision may occur from:
- Diabetic macular edema
- Diabetic retinopathy
- Fluctuating blood sugar levels
- Cataracts
Many patients have diabetic eye disease before they notice any symptoms, making regular eye exams especially important.
Glaucoma
Most forms of glaucoma do not cause blurry vision until significant damage has occurred.
Acute angle-closure glaucoma, however, may cause:
- Sudden blurry vision
- Severe eye pain
- Halos around lights
- Headache
- Nausea
This is a medical emergency.
Retinal Problems
Blurry vision may occur from:
- Retinal tears®
- Retinal detachment®
- Macular hole®
- Macular pucker®
- Retinal vein occlusion®
- Vitreous hemorrhage®
These conditions often require prompt evaluation by an ophthalmologist.
Eye Infections and Inflammation
Blurry vision may accompany:
- Pink eye (conjunctivitis)
- Keratitis
- Corneal ulcers
- Uveitis
- Corneal abrasions
These conditions often produce redness, pain, tearing, or light sensitivity.
Neurologic Causes
Occasionally blurry vision is related to the brain rather than the eye.
Possible causes include:
- Migraine
- Stroke
- Optic neuritis
- Multiple sclerosis
- Brain tumors (rare)
These situations require urgent medical evaluation.
When Is Blurry Vision an Emergency?
Seek immediate medical attention if blurry vision occurs suddenly, especially if accompanied by:
- A curtain or shadow over your vision
- New flashes of light
- Numerous new floaters
- Eye pain
- Double vision
- Severe headache
- Weakness or numbness
- Difficulty speaking
- Facial drooping
- Sudden vision loss in one or both eyes
Prompt evaluation can sometimes prevent permanent vision loss.
How Is Blurry Vision Diagnosed?
A comprehensive eye examination may include:
- Visual acuity testing
- Refraction (glasses prescription)
- Slit lamp examination
- Dilated retinal examination
- Eye pressure measurement
- Optical Coherence Tomography (OCT)
- Retinal photography
- Corneal topography
- Tear film evaluation
- Visual field testing when appropriate
These tests help identify the underlying cause rather than simply treating the symptom.
Treatment for Blurry Vision
Treatment depends entirely on the underlying cause.
Options may include:
- Updated Glasses or Contact Lenses
- Dry Eye Treatment
- Cataract Surgery
- LASIK or Vision Correction
Patients with retinal disease may benefit from:
- Anti-VEGF injections
- Laser treatment
- Vitrectomy surgery
- Ongoing retinal monitoring
Glaucoma Treatment may include:
- Eye drops
- Laser procedures
- MIGS
- Glaucoma surgery
Can Blurry Vision Come and Go?
Yes. Intermittent blurry vision is often caused by:
- Dry eyes
- Eye fatigue
- Blood sugar fluctuations
- Contact lens problems
- Migraines
- Changes in focusing ability
However, recurring episodes should still be evaluated by an eye doctor.
Can Stress Cause Blurry Vision?
Stress itself usually does not damage the eyes, but it can contribute to:
- Eye strain
- Dry eyes
- Migraine-related visual symptoms
- Temporary focusing problems
Persistent blurry vision should never be assumed to be caused solely by stress.
Can Screen Time Cause Blurry Vision?
Extended computer use may lead to digital eye strain, causing:
- Temporary blurry vision
- Dry eyes
- Difficulty refocusing
- Eye fatigue
- Headaches
The 20-20-20 rule and regular blinking can help reduce symptoms.
What Should I Do If My Vision Suddenly Becomes Blurry?
If your vision suddenly becomes blurry, especially in one eye or if it is associated with pain, flashes, floaters, weakness, or other neurological symptoms, seek emergency medical care immediately. If the change is gradual and painless, schedule a comprehensive eye examination as soon as possible.
Frequently Asked Questions
Why is my vision blurry all of a sudden?
Sudden blurry vision can result from retinal problems, eye inflammation, glaucoma, stroke, migraine, or changes in blood sugar. Sudden vision changes should always be evaluated promptly.
Why is one eye blurry but not the other?
Blurred vision in one eye may be caused by cataracts, macular degeneration, retinal disease, corneal problems, optic nerve disease, or a difference in prescription between the eyes.
Can dry eyes really cause blurry vision?
Yes. Dry eye disease is one of the most common causes of fluctuating blurry vision. Vision often improves temporarily after blinking or using lubricating eye drops.
Does blurry vision always mean I need glasses?
No. Although glasses are a common solution, blurry vision can also be caused by cataracts, retinal disease, glaucoma, dry eye, diabetes, infections, or neurological conditions.
When should I worry about blurry vision?
Seek immediate care if blurry vision develops suddenly, is associated with eye pain, flashes, floaters, a curtain over vision, weakness, numbness, difficulty speaking, or sudden vision loss.
Can cataracts cause blurry vision?
Yes. Cataracts are one of the leading causes of gradually worsening blurry vision, glare, halos around lights, and difficulty driving at night.
Why is my vision blurry after looking at a computer?
Computer use reduces blinking and contributes to dry eye and digital eye strain. These can temporarily blur vision, especially after prolonged screen time.
Can high blood sugar cause blurry vision?
Yes. Elevated blood sugar can temporarily change the shape of the eye's natural lens, causing fluctuating blurry vision. Diabetes can also lead to diabetic retinopathy and diabetic macular edema.
Why is my vision blurry in the morning?
Morning blurry vision may result from dry eye, corneal swelling, contact lens overwear, or underlying eye conditions. If it occurs regularly, an eye exam is recommended.
Can blurry vision be permanent?
Some causes of blurry vision are easily corrected, while others can lead to permanent vision loss if left untreated. Early diagnosis offers the best chance of preserving vision.
Related Eye Conditions
Patients experiencing blurry vision may also benefit from learning about:
- Cloudy vision
- Double vision
- Distorted vision
- Difficulty seeing at night
- Vision changes
- Dry eye disease
- Cataracts
- Macular degeneration
- Diabetic eye disease
- Glaucoma
- Flashes and floaters
- Retinal detachment
Patient Testimonials
Don't Ignore Blurry Vision
Blurry vision is often treatable, but in some cases it can signal a serious eye condition that requires prompt care. Whether your vision has changed gradually or suddenly, our experienced ophthalmologists and optometrists use advanced diagnostic technology to identify the cause and recommend the most appropriate treatment.
Schedule your comprehensive eye examination today to protect your vision and receive personalized care from New Hampshire's trusted eye specialists for more than 50 years.