Blurred Vision at Night? 7 Common Causes & When to Worry

Written by Swathi Kilari, MD

Medically reviewed by Syed Azmal Mahmood MD (Endocrinology), FCPS, MACP, MACE

Last reviewed October 6, 2026

Blurred vision at night is common, and it often has an understandable cause. In dim light, your pupils open wider and your eyes have less light to work with, so small focusing problems and certain eye conditions become easier to notice. Refractive errors can cause blurry vision and halos around bright lights, and cataracts can cause trouble seeing at night along with glare or halos around headlights, according to the National Eye Institute (NEI).

People describe nighttime vision problems in different ways. Some have mild difficulty seeing in low light, while others see fuzzy headlights, halos or starbursts around streetlights, or struggle to adjust when moving from light to dark. True loss of night vision (night blindness) is a distinct problem. Poor night vision should not be dismissed as a normal part of aging, because several eye conditions can be responsible.

This guide explains seven possible causes of blurred vision at night, why headlights can look blurry, and what signs mean you should see an eye doctor or seek urgent care. It also covers how the cause is found and what you can do in the meantime. Because the same symptom can come from very different problems, an eye exam is the best way to find out what is going on for you.

Important: Seek emergency care right away if your vision suddenly becomes blurry or disappears, or if blurred vision comes with severe eye pain, a painful red eye, severe headache, vomiting, weakness, facial drooping, or trouble speaking. This article is general information, not a diagnosis. Do not drive if you cannot see clearly enough to do so safely.

Quick Answer: Why Is My Vision Blurry at Night?

Blurred vision at night can be caused by astigmatism or another refractive error, an outdated glasses prescription, dry eye, cataracts, glare, diabetes-related eye problems, or other eye conditions. Difficulty seeing in low light can also have specific causes such as night blindness. Sudden vision changes, or blurred vision with severe eye pain or neurological symptoms, require urgent medical attention.

For a broader look at daytime and nighttime causes, see our related guide on blurred vision after eating, which covers blood sugar and blood pressure triggers.

What Does Blurred Vision at Night Feel Like?

People use many different words for it, and the description can offer clues. Common experiences include:

• Objects that look blurry or hazy
• Headlights that seem excessively bright
• Halos or rings around lights
• Street signs that are harder to read
• Difficulty recognizing faces in dim light
• Trouble adjusting when entering a dark room
• Reduced contrast between objects
• Eye strain while driving at night

These experiences may be described as blurry vision at night, poor night vision, difficulty seeing at night, glare, or halos around lights. They are symptoms, not diagnoses, and several of them can overlap.

7 Common Causes of Blurred Vision at Night

These causes are not equally common. Refractive errors, for example, are far more common than glaucoma. Each section below explains what the condition is, why it can affect nighttime vision, what clues to watch for, and what to do.

1. Refractive Errors or an Outdated Glasses Prescription

Refractive errors happen when the eye does not bend light correctly, so images do not focus sharply on the retina. They include nearsightedness (myopia), farsightedness (hyperopia), astigmatism and presbyopia. The NEI describes refractive errors as the most common type of vision problem and notes that they can cause blurred or hazy vision.

At night, the pupil widens, which can make small focusing errors more noticeable. Bright lights against a dark background may look fuzzy or surrounded by halos or glare. Astigmatism in particular can make lights look streaked or distorted.

Clues that a refractive error may be involved include:

• Vision that is clearer with glasses or contact lenses
• Difficulty reading road signs
• Squinting
• Headaches or eye strain
• Headlights that look fuzzy

An outdated prescription can produce the same symptoms. A comprehensive eye exam can determine whether your prescription needs updating. If you notice frequent headaches with vision strain, our guide on what causes headaches may help you describe your symptoms to a clinician.

2. Cataracts

A cataract is a clouding of the eye’s natural lens. Instead of passing cleanly through the lens to form a clear image, light scatters, which can make vision look cloudy or blurry. Cataracts are more common with age, but they can occur for other reasons too.

Symptoms may include blurry or cloudy vision, difficulty seeing at night, headlight glare, halos or starbursts around lights, faded colors, and a growing need for brighter lighting. Both the NEI and the Mayo Clinic list trouble seeing at night and sensitivity to glare among cataract symptoms. The American Academy of Ophthalmology (AAO) offers additional background.

Symptoms such as halos do not prove that you have a cataract, because other conditions can cause them. Only an eye exam can tell.

Night driving getting harder? Increasing glare from headlights or difficulty seeing road signs at night can be a good reason to schedule an eye exam.

3. Dry Eye

Dry eye happens when your eyes do not make enough tears or when the tear film is unstable, so the surface of the eye is not smooth. A rough surface can scatter light and cause intermittent blurring. Other symptoms include burning or stinging, a gritty feeling, redness, excessive tearing, and discomfort with contact lenses.

The AAO notes that dry eye can cause blurred vision and may be linked to long periods of screen use, contact lenses, certain medications, and environmental conditions. The NEI also provides an overview.

Symptoms may feel worse in the evening after a long day of screen use, because people tend to blink less when they focus on screens. That does not mean dry eye causes nighttime blur in everyone. If your blurring clears when you blink, dryness may be part of the picture, but an eye-care professional can confirm it.

4. Glare and Halos Around Lights

Glare and halos are visual symptoms rather than diseases. Bright headlights, streetlights and other small, intense light sources can appear to have halos, starbursts, glare or fuzzy edges. Several things can contribute, including:

• Refractive errors
• Cataracts
• Dry eye
• Irregularities in the cornea
• Certain other eye conditions

This is why a person who asks “Why are headlights blurry at night?” can get very different answers. Halos do not automatically mean cataracts. The cause may be a simple prescription change, or it may be something that needs treatment. An eye exam helps sort out which.

5. Glaucoma or Other Eye Diseases

Some eye diseases affect vision gradually and may not be obvious at first. Glaucoma is a group of conditions that damage the optic nerve. The Mayo Clinic explains that early open-angle glaucoma often has few noticeable symptoms, so people may not realize anything is wrong until vision is affected.

Acute angle-closure glaucoma is different. It can cause sudden blurred vision with severe eye pain, redness, headache, nausea or vomiting, and it needs immediate treatment, as the NEI and Mayo Clinic describe.

The key distinction is the speed and severity of symptoms:

• Gradual difficulty at night: arrange an eye exam.
• Sudden blurry vision with severe eye pain, redness, or nausea: seek urgent medical care.

Glaucoma is usually detected through an eye exam that checks eye pressure and the optic nerve, not through blurry night vision alone.

6. Diabetes and Diabetic Eye Disease

Diabetes can affect vision in several ways. Changing blood glucose levels can temporarily alter the lens and cause fluctuating blurry vision. Over time, diabetes also raises the risk of diabetic eye disease. Diabetic retinopathy damages the blood vessels in the retina and can lead to vision problems if it is not found and managed.

Blurred night vision alone does not mean someone has diabetes. If you are already living with the condition, regular dilated eye exams are an important part of care, since early eye disease may not cause symptoms. Learn more in our guides to diabetes symptoms and blood sugar.

If you have diabetes and notice new or worsening vision changes, talk with your healthcare professional and keep up with recommended eye exams.

7. Vitamin A Deficiency or Night Blindness

Night blindness (nyctalopia) is difficulty seeing in low light. It is different from ordinary nighttime blur, and it can have several causes, including certain retinal disorders, vitamin A deficiency, cataracts and other eye conditions. MedlinePlus explains that the cause determines the treatment.

The NEI lists night blindness and blurry or hazy vision among problems associated with low vision, and notes that more than one eye condition can contribute. Vitamin A is needed for normal vision, according to the NIH Office of Dietary Supplements. Deficiency is uncommon in the United States but can occur with certain medical conditions or very limited diets.

Do not self-treat suspected vitamin A deficiency with high-dose supplements, because too much vitamin A can be harmful. Persistent trouble seeing in dim light should be evaluated to find the underlying cause. For food-based ways to eat a varied diet, see our guides to nutrient-dense foods and what a balanced diet is.

Comparison of Possible Causes

This table is a general guide. It cannot tell you which cause applies to you.

Why Are Headlights Blurry or Surrounded by Halos at Night?

Headlights are a particularly hard test for the eyes. They are very bright, they are small and concentrated light sources, and they appear against a dark background. Your pupils are also wider at night, which lets in more scattered light and can magnify small focusing errors.

Possible contributors include astigmatism, cataracts, dry eye, corneal irregularities and an outdated prescription. Refractive errors can cause glare or halos around bright lights, while cataracts can produce halos, starbursts and increased sensitivity to headlights, according to the NEI.

Starbursts happen when light is scattered or not focused precisely on the retina. If headlights are becoming harder to tolerate, schedule an exam rather than adjusting your driving habits alone.

Is Blurred Vision at Night a Sign of a Serious Problem?

Often it is not an emergency, but it should not be ignored. Blurred night vision is usually less urgent when it:

• Developed gradually
• Affects both eyes similarly
• Improves with appropriate glasses
• Comes with mild dryness or eye strain

It needs a medical evaluation when it is new or getting worse, affects your driving, occurs mainly in one eye, comes with increasing glare or halos, or happens in someone with diabetes or another condition that can affect the eyes.

It can be an emergency if it begins suddenly or comes with severe pain or neurological symptoms.

When Should You See a Doctor for Blurred Vision at Night?

Schedule an eye exam if:

• Your night vision is gradually getting worse.
• Headlights are increasingly difficult to tolerate.
• You often see halos or starbursts.
• You struggle to read signs at night.
• Your glasses or contact lens prescription no longer seems to help.
• You have persistent or recurring blurred vision.
• You have diabetes and notice vision changes.

Seek urgent medical care if:

• Your vision suddenly becomes blurry or disappears.
• You develop severe eye pain.
• Your eye becomes suddenly red and painful.
• Blurred vision comes with severe headache, nausea or vomiting.
• You suddenly see flashes of light or many new floaters.
• A dark curtain or shadow appears across your vision.
• Vision changes come with weakness, facial drooping, confusion or difficulty speaking.

For example, acute angle-closure glaucoma can cause sudden blurred vision, intense eye pain, redness, headache and nausea, and it requires immediate treatment. Flashes, new floaters or a shadow can signal a retinal detachment. The CDC lists sudden vision changes among the warning signs of stroke.

Do not wait to see whether a sudden loss of vision improves. Call 911 or go to the nearest emergency department.

Can You Improve Blurred Vision at Night?

The right step depends on the cause, so start by finding it. Some practical measures that may help include:

• Have your prescription checked.
• Keep your glasses clean and properly fitted.
• Follow contact lens hygiene instructions.
• Ask a professional how to manage dry eye symptoms.
• Use appropriate lighting when reading.
• Get regular comprehensive eye exams.
• Wear appropriate UV protection during the day.
• Avoid driving if you cannot see clearly enough to drive safely.

Home measures do not treat an underlying eye disease. If you have diabetes, keeping blood glucose in your target range and staying current with eye exams are important parts of protecting your vision. Our guide to the A1C test explains one common way glucose control is monitored.

How Is the Cause of Blurred Vision at Night Diagnosed?

An eye-care professional may check several parts of your visual system, including:

• Visual acuity (how clearly you see)
• Refraction (the glasses or contact lens prescription you need)
• Eye pressure
• The cornea, lens and retina
• The optic nerve
• Peripheral (side) vision
• A dilated eye exam, when appropriate

The NEI notes that a comprehensive dilated eye exam can help detect conditions linked to vision loss, including glaucoma and other eye diseases, sometimes before symptoms appear. Not everyone needs every test. The clinician chooses based on your symptoms and history.

Frequently Asked Questions About Blurred Vision at Night

Why is my vision blurry at night but clear during the day?

Low light widens your pupils and gives your eyes less to work with. That can make focusing problems, glare and certain eye conditions more noticeable at night. An eye exam can find out which one applies.

Why do headlights look blurry at night?

Astigmatism, cataracts, dry eye, corneal problems and an outdated prescription can all make headlights look blurry or surrounded by glare. The NEI notes that refractive errors can cause glare or halos around bright lights.

Why do I see halos around lights at night?

Halos can come from refractive errors, cataracts, dry eye, corneal changes and other conditions. They do not automatically mean cataracts. If halos are new or increasing, get your eyes examined.

Is blurry vision at night normal with aging?

Not simply. Aging raises the chance of conditions such as cataracts, but new or worsening night vision problems deserve an eye exam rather than being assumed to be normal.

Can astigmatism cause blurry vision at night?

Yes. Astigmatism can cause blurry or distorted vision, along with glare or halos around bright lights, according to the NEI. Glasses or contact lenses often correct it.

Can dry eyes cause blurry vision at night?

Yes. Dry eye can cause blurred vision, especially when the tear film becomes unstable, as the AAO explains. It may feel worse after a long day of screen use.

Is night blindness the same as blurry vision at night?

No. Night blindness refers to difficulty seeing in low light, while nighttime blur can have many other causes. Both deserve evaluation if they persist.

When is blurry vision at night an emergency?

Get emergency care for sudden vision changes or loss, severe eye pain, a painful red eye, new weakness or speech trouble, flashes or many new floaters, or a curtain-like shadow over your vision.

Key Takeaway

Blurred vision at night can result from common issues such as an outdated prescription, astigmatism, dry eye or glare. It can also be associated with cataracts, diabetes-related eye disease, glaucoma or other eye conditions. If your nighttime vision is getting worse, affecting your driving, or accompanied by new symptoms, schedule an eye exam. Sudden vision changes, severe eye pain or neurological symptoms need urgent medical attention.

Sources

1. National Eye Institute. Refractive Errors.
2. National Eye Institute. Astigmatism.
3. National Eye Institute. Cataracts.
4. National Eye Institute. Dry Eye.
5. National Eye Institute. Glaucoma.
6. National Eye Institute. Diabetic Retinopathy.
7. National Eye Institute. Low Vision.
8. National Eye Institute. Retinal Detachment.
9. National Eye Institute. Get a Comprehensive Dilated Eye Exam.
10. American Academy of Ophthalmology. What Are Cataracts?
11. American Academy of Ophthalmology. What Is Dry Eye?
12. Mayo Clinic. Cataracts: Symptoms and causes.
13. Mayo Clinic. Glaucoma: Symptoms and causes.
14. Mayo Clinic. Angle-closure glaucoma: Symptoms and causes.
15. MedlinePlus. Night blindness.
16. National Institutes of Health, Office of Dietary Supplements. Vitamin A: Health Professional Fact Sheet.
17. 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 at night 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.