Halos Around Lights: Causes, Symptoms, and When to Seek Care
Seeing halos or bright rings around lights may signal eye conditions, from dry eyes to cataracts—learn causes, symptoms, and treatment options.
Seeing halos around lights—those bright circles or colorful rings that radiate from headlights, street lamps, or other bright sources—can be disconcerting. While occasionally seeing halos is normal, especially at night or after looking at a bright light, persistent or sudden halos may indicate an eye condition that needs attention. This article explores why halos happen, the possible underlying causes, related symptoms, when they are serious, and how they are diagnosed and treated.
What Are Halos Around Lights?
Halos are circles or rings that appear to surround a bright light source. You may notice them at night when looking at headlights, street lamps, or illuminated signs. Sometimes, they appear as white halos; in other cases, they can be rainbow-colored or starburst patterns. Halos occur most noticeably in dim or dark conditions, but some people report seeing them in daylight when the lighting conditions are right.
- Temporary halos can happen after exposure to bright lights or after certain eye procedures.
- Persistent or sudden onset of halos should be evaluated by an eye care provider.
- Halos may be accompanied by symptoms such as blurred vision, pain, redness, or headaches.
What Causes Halos Around Lights?
Halos form when light is scattered or bent as it enters the eye, rather than traveling directly to the retina. Various factors or eye conditions can cause this light scatter, including:
- Dry eye syndrome: Irregularities in the tear film on the cornea can scatter incoming light, making halos more noticeable, especially in low light or at night.
- Cataracts: Clouding of the lens inside the eye causes light rays to bend or scatter, producing halos and glare, especially at night or in bright conditions.
- Glaucoma (especially acute forms): Elevated pressure inside the eye can affect the cornea, causing rainbow-colored halos, especially if glaucoma progresses rapidly.
- Incorrect or outdated eyeglass/contact lens prescription: Imperfect correction can result in blurred or scattered points of light, often causing halos, especially at night.
- Corneal edema: Swelling of the cornea, often related to eye surgery, injury, or disease, scatters light and causes halos.
- Recent eye surgery: Procedures like LASIK or cataract surgery can temporarily cause halos as part of the normal healing process.
- Keratoconus: Thinning of the cornea changes its shape, leading to irregular astigmatism and symptoms like halos and glare.
- Diabetic retinopathy: Changes in the blood vessels at the back of the eye can distort vision, resulting in halos around lights, particularly in advanced cases.
- Exposure to chemicals (like chlorine): This can temporarily disrupt the corneal surface and cause halos.
Common Causes and Their Mechanisms
| Condition | Mechanism | Typical Symptoms |
|---|---|---|
| Dry Eyes | Tear film irregularities scatter incoming light | Halos at night, dry sensation, irritation |
| Cataracts | Clouded lens bends and scatters light | Halos, glare, blurred vision, dull colors |
| Glaucoma (Acute) | Increased eye pressure distorts cornea | Rainbow halos, eye pain, nausea, blurred vision |
| Keratoconus | Thinned/irregular cornea causes light to scatter | Halos, starbursts, blurred/distorted vision |
| Outdated Prescription | Light not focused properly on retina | Blurry vision, halos, squinting |
| Diabetic Retinopathy | Damaged blood vessels distort vision | Halos, vision loss, floaters |
What Do Halos Look Like?
The appearance of halos can differ based on the underlying cause and the lighting conditions. Halos may be:
- Simple white rings around light sources.
- Rainbow-colored or multicolored circles—more often seen with conditions like acute angle-closure glaucoma or cataracts.
- Starburst effects, where light seems to radiate out in lines from the center.
- Accompanied by blurred vision, headaches, or eye discomfort.
If you notice a sudden change in the appearance or frequency of halos, particularly if they are colored, get prompt medical attention.
Are Halos Around Lights Ever Normal?
Temporary halos are not always a sign of serious eye disease. Some normal or non-serious causes include:
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- Looking at a bright light after being in the dark
- Experiencing halos after pupil-dilating eye drops at an exam
- Recently undergoing eye surgery (such as LASIK or cataract surgery)
However, if halos are persistent, worsening, or associated with other symptoms, seek an evaluation by an eye care professional as soon as possible.
Eye Conditions Linked to Halos Around Lights
Cataracts
Cataracts cause the natural lens of the eye to become cloudy, leading to light scatter, glare, and halos, especially at night or against bright lights. You might also notice:
- Blurry or dim vision
- Sensitivity to light
- Colors that seem faded
- Double vision in a single eye
Acute Angle-Closure Glaucoma
This urgent type of glaucoma results in a rapid spike in intraocular pressure, often producing sudden, colored halos (rainbow-like), severe eye pain, nausea, headache, and vision loss. This is a medical emergency that requires prompt treatment to preserve sight.
Dry Eye Syndrome
Dry eyes create a rough or unstable surface on the cornea, leading to the scattering of light and making halos prominent. Other symptoms include stinging, burning, redness, or the sensation of something in the eye.
Keratoconus
In keratoconus, the cornea thins and bulges outward, becoming cone-shaped. This causes distorted and scattered light, resulting in halos, glare, starbursts, and blurry vision—often starting in adolescence or young adulthood.
Diabetic Retinopathy
Advanced complications from diabetes can cause blood vessel changes in the back of the eye (retina), sometimes distorting vision and producing halos, along with floaters and vision loss.
Uncorrected Vision/Outdated Prescriptions
Wearing glasses or contacts with an incorrect prescription can leave vision blurry, causing light scatter and halos—especially at night.
Other Causes of Halos
- Swelling of the cornea (corneal edema) from injury, disease, or post-surgery healing
- Eye inflammation (e.g., uveitis, keratitis)
- Recovery from eye surgery, such as LASIK, PRK, or lens replacement
- Drug or chemical exposure (e.g., pool water, cleaning agents)
- Contact lens overwear or poor fit
When to Seek Medical Care
Contact an eye doctor promptly if halos:
- Appear suddenly or worsen quickly
- Are accompanied by eye pain, severe headache, nausea, or vomiting
- Are associated with redness, swelling, or blurred vision
- Interfere with driving or daily activities
If you suspect acute glaucoma (rainbow halos, pain, sudden vision changes), go to the emergency room immediately—delayed treatment can lead to permanent vision loss.
Diagnosing the Cause of Halos
Your eye care provider will perform several steps to determine the cause, which may include:
- Reviewing your medical and vision history
- Conducting a comprehensive eye exam
- Measuring intraocular pressure to check for glaucoma
- Examining the cornea and lens for cataracts or swelling
- Performing special imaging (such as OCT or slit-lamp exams)
- Assessing your prescription and checking for optical issues
Treatment and Management Options
The best treatment for halos depends on the underlying cause:
- Dry eye: Artificial tears, lubricating ointments, prescription drops, and addressing environmental triggers.
- Cataracts: Cataract surgery is often the definitive treatment. Surgery replaces the cloudy lens with a clear artificial one, eliminating halos caused by the cataract.
- Glaucoma: Emergency treatment (usually medications or surgery) to lower intraocular pressure.
- Outdated prescriptions: Updating glasses or contacts often resolves light scatter and halos.
- Keratoconus: Management may include custom contact lenses, corneal cross-linking, or, rarely, corneal transplant.
- Corneal edema or swelling: Medical or surgical interventions to reduce swelling as needed.
- Post-surgical halos: These often improve as the eyes heal. In persistent cases, adjusting the lens or a surgical revision may help.
Mild and transient halos caused by minor dry eye, recent surgery, or environmental exposure often improve with conservative care and time.
Can Halos Be Prevented?
- See your eye doctor regularly for comprehensive eye exams.
- Follow up promptly if you experience new or changing night vision symptoms.
- Protect your eyes from chemicals, airborne irritants, and excess sunlight (wear sunglasses and goggles as recommended).
- Manage underlying health conditions, such as diabetes or immune disorders, per your physician’s advice.
Some causes—such as aging or inherited corneal conditions—may not be preventable, but early intervention can reduce the risk of vision loss or further complications.
Frequently Asked Questions (FAQs)
Is it normal to see halos around lights?
Occasional halos after looking at bright sources or with tired eyes are common. Persistent, colored, or sudden halos—especially with pain or blurred vision—are not normal and require evaluation.
Do halos around lights always mean I need surgery?
No. Surgery is sometimes needed, such as in cataracts or some glaucoma cases, but minor causes (like dry eyes or uncorrected prescriptions) can often be managed non-surgically. Your eye doctor will recommend a plan based on the cause.
What’s the difference between halos and glare?
Halos are rings or circles around light sources, while glare is overall brightness or difficulty seeing against strong light. Both can have similar causes but describe slightly different effects.
Can children experience halos?
Yes, children can experience halos, but this is less common. Any persistent or dramatic vision change in children warrants evaluation, as some conditions linked to halos (such as congenital glaucoma) are serious.
How are halos different from floaters?
Halos are light phenomena seen around bright objects. Floaters are specks, threads, or blobs drifting across your field of vision, usually due to changes in the jelly (vitreous) inside the eye. They have different causes and typically are not linked.
Can over-wearing contact lenses cause halos?
Yes. Contacts that are dirty, poorly fitted, or overworn can irritate the cornea or cause swelling, resulting in halos and other vision changes. Always follow your eye care provider’s guidance for lens care and wear time.
Key Takeaways
- Halos around lights can be caused by dry eyes, cataracts, glaucoma, keratoconus, vision prescription errors, or as a symptom of recovery from eye procedures.
- Sudden, colorful, or severe halos—especially with pain or other vision changes—require prompt medical attention.
- Many causes of halos are treatable; early evaluation by an eye professional is key to preventing serious vision loss.
References
- https://www.specsavers.ie/eye-health/halos-around-lights
- https://www.allaboutvision.com/conditions/symptoms/halo-lights/
- https://www.eurekahealth.com/resources/why-do-i-have-halos-around-lights-en
- https://www.healthline.com/health/eye-health/sudden-blurred-vision
- https://www.medicalnewstoday.com/articles/157510
- https://my.clevelandclinic.org/podcasts/health-essentials/halo-vision-should-you-be-worried-with-nicole-bajic-md
- https://eyesofcolorado.org/vision-changes-at-41-55-years-of-age/
- https://www.illinoiseyecenter.com/understanding-halo-and-glare-why-you-might-be-seeing-circles-of-light-especially-in-winter/
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