Blurred Vision That Comes and Goes: Causes & When to Worry

Written by Swathi Kilari, MD

Medically reviewed by Lindsay Ewan MD, MPH

Last reviewed October 6, 2026

Blurred vision that comes and goes can have many possible explanations. Sometimes the cause is temporary, such as an unstable tear film or another problem on the surface of the eye. In other cases, recurring episodes are linked to refractive errors, blood glucose changes, migraine, contact lens problems, or an underlying eye condition.

The pattern of your symptoms matters. Does it affect one eye or both? Does it last seconds or hours? What were you doing when it started, and does your vision fully return to normal? These details help an eye-care professional narrow down the cause.

The core message of this guide is simple: intermittent does not necessarily mean harmless. A sudden or significant episode should not be dismissed just because your vision returned to normal. Below, we cover eight common causes, how to tell a mild problem from an urgent one, and what you can do next.

Important: Seek emergency care right away for sudden vision loss (even if it clears), severe eye pain, a painful red eye, new flashes of light, a curtain-like shadow, new double vision, or vision changes with weakness, numbness, facial drooping, trouble speaking, or confusion. This article is general information, not a diagnosis.

Quick Answer: Why Does My Vision Get Blurry and Then Clear Up?

Blurred vision that comes and goes can be caused by dry eye, an unstable tear film, refractive errors, contact lens problems, eye strain, blood sugar changes, migraine-related visual symptoms, or other eye conditions. The cause depends on how long episodes last, whether one or both eyes are affected, and whether other symptoms occur. Sudden vision loss, severe eye pain, flashes, a curtain-like shadow, or neurological symptoms require urgent medical attention.

The National Eye Institute (NEI) notes that refractive errors commonly cause blurry vision, and dry eye can also affect vision. Intermittent blur is a symptom, not a diagnosis, so the sections below explain how to sort through the possibilities.

What Does Intermittent Blurred Vision Look or Feel Like?

People describe episodes in many ways. You might notice:

• Vision that turns hazy for a few seconds or minutes
• Objects that briefly go out of focus
• Vision that clears after blinking
• Temporary difficulty reading
• One eye that looks blurry and then normal again
• Fluctuating vision during screen use
• Temporary halos around headlights or bright lights
• Objects that look distorted or wavy
• Blur that happens during certain activities or at certain times of day

These experiences are sometimes called fluctuating vision, temporary blurry vision, or recurring blurred vision. All of them describe a symptom that has more than one possible cause.

8 Common Causes of Blurred Vision That Comes and Goes

These causes are not equally common, and some overlap. Only an eye exam can tell which applies to you.

1. Dry Eye and an Unstable Tear Film

The tear film creates a smooth optical surface on the front of the eye. When tears evaporate too quickly or are not produced in adequate amounts, that surface becomes uneven and vision can fluctuate. Blinking spreads fresh tears across the eye, so clarity may improve for a moment.

The NEI lists dryness, burning, a gritty feeling, redness, light sensitivity, and blurred vision among the symptoms of dry eye. According to the American Academy of Ophthalmology (AAO), screen use, environmental conditions, certain medications, and some health conditions can contribute.

If your vision blurs during long stretches of screen use and improves after blinking, dry eye may be a factor. That pattern is a clue, not a diagnosis. If episodes keep coming back, an eye-care professional can check your eyes.

2. Refractive Errors or an Outdated Prescription

Refractive errors include nearsightedness (myopia), farsightedness (hyperopia), astigmatism, and presbyopia. The NEI describes them as among the most common causes of blurry vision, and they can also cause haziness, glare, halos, eye strain, and headaches.

Vision may seem to fluctuate depending on distance, lighting, fatigue, reading, screen use, or how long you have been focusing. An outdated glasses or contact lens prescription can produce the same effect. A comprehensive eye exam can show whether your prescription needs updating.

For more on one common type, see the NEI’s overview of astigmatism. If headaches come with your vision changes, our guide to what causes headaches may help.

3. Contact Lens Problems

Contact lenses can cause intermittent blur when they dry out, move, collect deposits, or do not fit well. Problems are more likely when lenses are worn longer than recommended, when hygiene is poor, or when people sleep in lenses that are not approved for overnight wear. The CDC provides guidance on healthy contact lens habits.

Mild blur from a dry or shifted lens may improve after you blink or remove and clean the lens as directed. Corneal irritation or infection is less common but more serious.

Safety warning: If you wear contacts and have blurred vision with significant pain, redness, light sensitivity, discharge, or a sudden decrease in vision, take the lenses out and get prompt eye-care evaluation. Do not keep wearing them to see whether things improve.

4. Blood Sugar Changes and Diabetes

Changes in blood glucose can temporarily affect vision, because high glucose can alter the lens, as the Mayo Clinic explains. This is different from diabetic eye disease, which develops over time.

Diabetic retinopathy damages blood vessels in the retina, and diabetic macular edema (swelling in the central retina) can cause blurry or wavy vision, according to the NEI. Regular dilated eye exams are important for people with diabetes, because early disease may not cause symptoms.

This does not mean that vision that comes and goes signals diabetes. Recurring vision changes in someone with diabetes deserve medical and eye-care evaluation. For background, see our guides to signs of high blood sugar and diabetes symptoms, and our article on blurred vision after eating.

5. Migraine With Visual Symptoms

Migraine can cause temporary visual symptoms, sometimes before or during a headache. These can include blurred or disturbed vision, shimmering or flashing effects, zigzag patterns, blind spots, and light sensitivity. The National Institute of Neurological Disorders and Stroke describes migraine and its aura symptoms.

New visual symptoms should not automatically be assumed to be migraine. That is especially true when they are sudden, affect only one side or one eye, or differ substantially from earlier episodes. A clinician can help sort this out.

6. Eye Strain and Prolonged Screen Use

Long periods of close-up focusing can tire the eyes. People also blink less when looking at screens, which can lead to dryness. Typical effects include temporary trouble refocusing from near to far, tired eyes, and headaches. The AAO offers tips for comfortable computer use.

Screen-related symptoms often overlap with dry eye and uncorrected refractive errors. If blur mostly shows up after computer work, phone use, reading, or long periods of concentration, and improves with rest, blinking, and changing focus, eye strain or dryness may be contributing.

If rest does not help, or symptoms keep returning, get an eye exam rather than assuming it is just strain.

7. Cataracts and Other Eye Conditions

Cataracts usually cause more persistent changes than brief episodes. Even so, people with recurring blur should not assume every episode is eye strain. The NEI lists hazy vision, glare, halos, trouble seeing at night, and faded colors among cataract symptoms.

Other conditions can also be involved, including glaucoma, retinal disease, macular conditions such as age-related macular degeneration, corneal disorders, and eye inflammation. The NEI identifies cataracts, glaucoma, diabetic retinopathy, and age-related macular degeneration among important causes of vision impairment.

Many of these conditions develop gradually and may not hurt. That is one more reason that recurring blurred vision calls for an eye exam. Our article on blurred vision at night discusses glare and halos in more depth.

8. Medication, Blood Pressure, or Other Health Conditions

Visual symptoms can sometimes occur alongside medication side effects, changes in blood pressure, certain systemic conditions, or neurological disorders. This does not mean you should worry about a long list of diseases.

The timing and the other symptoms you notice help a clinician decide whether the cause is in the eye, related to a medicine, tied to another health condition, or neurological. Bring a list of your medicines and supplements to your appointment. Do not stop or change a prescribed medicine on your own. If dizziness or lightheadedness comes with your blur, see our guide on what causes dizziness.

Why Does My Vision Go Blurry Then Clear Up?

The way your vision clears can offer clues about the cause.

• Blinking improves it: This may suggest dryness or a tear-film problem.
• Changing focus improves it: This may relate to focusing difficulty or eye strain.
• It happens after screen use: Dry eye and visual fatigue may both contribute.
• It happens with changes in blood sugar: Glucose fluctuations may be affecting vision.
• It happens with headache or visual patterns: Migraine may be one possibility.
• It happens suddenly in one eye: This is more concerning and should not be dismissed just because it resolves.

These patterns can overlap, and none of them confirms a diagnosis.

Is Blurred Vision That Comes and Goes Serious?

It depends on the pattern. A three-level view can help.

Sometimes less concerning: The blur is mild, brief, and occasional; it affects both eyes; it clearly goes along with dryness or long screen use; and vision completely returns to normal.

Schedule an eye exam if:

• Episodes keep recurring or are becoming more frequent
• Vision does not fully return to normal
• One eye is repeatedly affected
• You have diabetes
• You notice increasing glare or halos
• Reading or driving is getting harder

Seek urgent medical attention if you notice: a sudden major vision change, sudden vision loss, severe eye pain, new flashes or many new floaters, a curtain or shadow over your vision, new double vision, or neurological symptoms.

When Is Intermittent Blurred Vision an Emergency?

Warning: Do not wait to see whether these symptoms pass. Call 911 or go to the nearest emergency department.

Seek urgent medical attention if blurred vision comes with any of the following:

• Sudden loss or major reduction of vision
• Severe eye pain
• A red, painful eye
• New flashes of light
• A sudden increase in floaters
• A dark curtain or shadow across your vision (these can signal a retinal detachment)
• New double vision
• Severe headache
• Weakness or numbness
• Facial drooping
• Trouble speaking
• Confusion
• Loss of balance

The CDC lists sudden vision changes, trouble speaking, weakness, and severe headache among the warning signs of stroke.

Temporary Vision Loss in One Eye

Sudden, temporary loss of vision in one eye should be taken seriously, even when vision comes back. Ophthalmology references note that transient monocular vision loss can have vascular causes and may need urgent evaluation. The fact that vision returned does not make the episode harmless. Get medical care right away.

Intermittent Angle Closure

Rarely, episodes of blurred vision or halos accompanied by eye pain or headache can occur with intermittent angle closure, a form of glaucoma. The Mayo Clinic describes how acute angle-closure glaucoma causes sudden blurred vision, severe eye pain, redness, and nausea, and needs immediate treatment. This is an important reason not to label every recurring episode as “just dry eyes.”

Blurred Vision That Comes and Goes in One Eye vs. Both Eyes

Both eyes. Possible contributors include dry eye, refractive errors, screen-related strain, blood glucose changes, migraine, and systemic factors.

One eye. One-eye episodes can be more concerning, especially when they are:

• Sudden
• Accompanied by significantly darker vision
• Painful
• Paired with flashes or floaters
• Accompanied by a curtain-like shadow
• Becoming more frequent

One-eye blur does not always mean an emergency. It does mean the pattern deserves a more careful assessment, so tell your clinician which eye is affected each time.

What Can You Do When Your Vision Becomes Blurry?

These steps are practical and low risk. They do not replace medical care.

• Stop driving if your vision is not clear enough to drive safely.
• Blink and let your eyes rest.
• Take regular breaks from screens.
• Avoid rubbing your eyes.
• Follow good contact lens hygiene.
• Use lubricating eye drops if they are recommended for your situation.
• Arrange an eye exam if symptoms recur or persist.

Keep a Symptom Diary

A short log can help your clinician see the pattern. Here is an example:

Also note possible triggers such as meals, exercise, bright light, or headaches.

How Is Intermittent Blurred Vision Diagnosed?

Diagnosis depends heavily on the pattern of your episodes. An eye-care professional may assess:

• Visual acuity
• Refraction
• Eye movements and pupils
• The cornea and tear film
• Eye pressure
• The lens
• The retina and optic nerve
• Peripheral vision
• A dilated eye exam, when appropriate

The NEI explains that a comprehensive dilated eye exam can help clinicians look for conditions affecting the retina and other structures involved in vision.

Your history is especially important. Be ready to tell the clinician how often episodes happen, how long they last, which eye is affected, what you were doing beforehand, whether blinking helps, whether headaches or pain occur, and whether your vision returns completely.

Intermittent Blurred Vision: What the Pattern May Suggest

Patterns can overlap, and symptoms alone cannot determine the diagnosis.

Frequently Asked Questions

Why does my vision get blurry and then clear up?

Common reasons include temporary dryness, focusing strain, a prescription problem, contact lens issues, blood sugar changes, or migraine. The cause depends on how long episodes last and whether other symptoms occur. If it keeps happening, get an eye exam.

Why does my blurry vision come and go?

The tear film, focusing system, blood sugar, and nervous system can all affect how clearly you see from moment to moment. Because several causes are possible, a pattern log and an eye exam can help identify yours.

Is intermittent blurred vision normal?

Occasional, brief blur that clears completely may be fairly common, but recurring episodes should not simply be considered normal. Schedule an eye exam if episodes are frequent, getting worse, or affect daily activities.

Can dry eyes cause vision to come and go?

Yes. The NEI notes that dry eye can affect vision, and an unstable tear film can make clarity fluctuate. Blinking may briefly improve it.

Can dehydration cause temporary blurred vision?

It may contribute in some people, but it is not a universal explanation. Dry eye, prescription problems, and other eye or health conditions are common causes. Do not assume recurring blur is just dehydration.

Can blood sugar cause blurry vision that comes and goes?

Yes. Changes in blood glucose can temporarily affect the lens, according to the Mayo Clinic. People with diabetes should discuss recurring vision changes with their care team and keep up with eye exams.

Why is one eye blurry sometimes?

One-eye blur can come from dryness, a lens problem, a prescription difference between the eyes, or an eye condition. Repeated or sudden one-eye episodes deserve prompt medical assessment.

Can eye strain cause temporary blurred vision?

Yes. Long periods of close focus and reduced blinking can cause tired eyes and temporary blur. If rest and screen breaks do not help, have your eyes checked, since strain can overlap with dry eye and uncorrected refractive errors.

Can migraines cause intermittent blurry vision?

Yes. Migraine can cause temporary visual symptoms, as the NINDS describes. New or unusual visual symptoms should still be evaluated rather than assumed to be migraine.

When should I see a doctor for blurry vision that comes and goes?

See an eye-care professional if episodes recur, become more frequent, affect one eye repeatedly, or interfere with reading or driving. Seek urgent care for sudden vision loss, severe eye pain, flashes, a curtain-like shadow, or neurological symptoms.

Can intermittent blurred vision be a sign of a stroke?

It can be, although most intermittent blur has other causes. Sudden vision loss, double vision, weakness, facial drooping, or trouble speaking need emergency care, as the CDC explains. Do not wait to see whether symptoms clear.

Can blurred vision come and go with glaucoma?

The common form of glaucoma usually develops slowly without obvious symptoms. Rarely, intermittent angle closure can cause episodes of blur or halos with eye pain or headache, as the Mayo Clinic describes. Seek urgent care for sudden blur with severe eye pain.

Key Takeaway

Blurred vision that comes and goes has many possible causes. Temporary dryness, refractive errors, screen-related eye strain, contact lenses, migraine, and blood glucose changes are among them. Persistent or increasingly frequent episodes need evaluation, and one-eye episodes deserve particular attention. Sudden vision loss, severe eye pain, flashes or floaters, a curtain-like shadow, or neurological symptoms require urgent medical care.

Sources

1. National Eye Institute. Refractive Errors.
2. National Eye Institute. Astigmatism.
3. National Eye Institute. Dry Eye.
4. National Eye Institute. Diabetic Retinopathy.
5. National Eye Institute. Cataracts.
6. National Eye Institute. Age-Related Macular Degeneration.
7. National Eye Institute. Retinal Detachment.
8. National Eye Institute. Get a Comprehensive Dilated Eye Exam.
9. American Academy of Ophthalmology. What Is Dry Eye?
10. American Academy of Ophthalmology. Computer Usage and Your Eyes.
11. Mayo Clinic. Hyperglycemia in diabetes: Symptoms and causes.
12. Mayo Clinic. Angle-closure glaucoma: Symptoms and causes.
13. National Institute of Neurological Disorders and Stroke. Migraine.
14. Centers for Disease Control and Prevention. Contact Lenses.
15. Centers for Disease Control and Prevention. Stroke Signs and Symptoms.

Medical Disclaimer: This article is for general educational purposes only and is not a substitute for professional medical advice, diagnosis or treatment. Blurred vision can have many causes, some of them serious. Always talk with a doctor or eye care professional about symptoms that concern you, and call 911 or your local emergency number right away if you think you are having a medical emergency.