Vision Halos Around Lights and Glare: Causes, Symptoms and When to See an Optometrist
Halos around lights are rings or circles of brightness that appear around light sources — headlights, streetlamps, or indoor lights — and are one of the most common visual disturbances people notice, particularly at night. Whether you're seeing glowing circles around traffic lights or struggling to cope with glare on a bright day, these symptoms can have a range of causes, from correctable refractive errors such as astigmatism to conditions that warrant a thorough examination with an AHPRA-registered optometrist.
This guide explains what halos and glare are, why they occur, and how they are typically managed
What Are Halos Around Lights?
Halos around lights appear as circular rings or bands of brightness surrounding a light source. They form when light entering the eye is scattered or diffracted before reaching the retina rather than being sharply focused onto it. The result is a blurred halo effect that can range from a subtle glow to a bright, distinct ring.
They are most noticeable in low-light conditions, such as driving at night, when the pupils dilate to allow more light into the eye. The wider the pupil, the greater the opportunity for scattered light to interfere with clear vision.
Halos are not always a sign of a serious underlying condition. For many people, they reflect an uncorrected or under-corrected refractive error, something an updated spectacle or contact lens prescription can address. For others, they may indicate a condition that needs closer investigation.
What is Glare?
Glare is the visual discomfort or impairment caused by excessive or poorly distributed brightness within the field of vision, reducing contrast and making it difficult to see clearly. When light intensity overwhelms the eye's ability to adapt, the result is washed-out images, reduced contrast, or difficulty distinguishing fine detail.
There are several distinct types of glare, each with a different mechanism:
1. Disability glare
Directly impairs your ability to see by reducing contrast and visibility. Oncoming headlights at night are a common trigger.
2. Discomfort Glare
Causes eye strain or physical discomfort without necessarily reducing visual clarity. Fluorescent lighting and bright LED screens are frequent culprits.
3. Night Glare
Occurs when pupils dilate in low light, increasing sensitivity to artificial light sources such as car headlights or neon signs.
4. Veiling Glare
A diffuse haze caused by light scattering from environmental factors such as fog, reducing image contrast and sharpness.
5. Photostress Glare
Results from sudden exposure to intense light (such as a camera flash), causing temporary afterimages or visual impairment.
Common Causes of Halos and Glare
Astigmatism and Halos Around Lights
Astigmatism is one of the most frequent causes of halos around lights, particularly at night. It occurs when the cornea or lens has an irregular curvature — rather than being smoothly spherical, the surface curves unevenly, causing light to focus at multiple points rather than one precise location on the retina. The result is blurred or distorted vision and, commonly, noticeable halos or starburst patterns around light sources in low-light conditions.
Astigmatism halos around lights are typically most apparent when driving at night or looking at illuminated signs in dark environments. The pupils dilate in low light, which exacerbates the scattering effect caused by the irregular corneal shape. Astigmatism is a refractive error that can generally be addressed with corrective lenses—spectacles or toric contact lenses — or assessed for suitability for laser refractive surgery. Updating an outdated prescription is often the first and most straightforward step.
Cataracts
Cataracts cause clouding of the eye's lens, scattering light before it reaches the retina. This leads to increased glare sensitivity, reduced colour perception, and halos — symptoms that typically worsen gradually over time. Cataract surgery, which replaces the clouded lens with an artificial intraocular lens (IOL), may help reduce these visual disturbances, though some IOL types (particularly multifocal designs) can contribute to halos during the adjustment period.
Dry Eyes
Dry eye disease disrupts the smooth optical surface of the eye by reducing the quality or quantity of the tear film, causing light to scatter unevenly. It is a surprisingly common cause of night-time halos and glare that often goes unrecognised. Symptoms tend to fluctuate throughout the day and are frequently worse in dry, air-conditioned, or windy environments.
Glaucoma
In acute angle-closure glaucoma, a sudden increase in intraocular pressure can cause halos around lights alongside eye pain, headache, nausea, and blurred vision. This combination of symptoms represents a medical emergency. If you experience sudden-onset halos accompanied by any of these symptoms, seek urgent eye care without delay.
Keratoconus
Keratoconus is a progressive condition in which the cornea gradually thins and develops a cone-like shape, distorting the way light is focused. It can produce significant halos, ghosting, and glare. According to Healthdirect Australia, keratoconus most commonly affects people in their teens and twenties and often runs in families. Management options range from rigid contact lenses to corneal cross-linking or, in advanced cases, corneal transplantation.
Corneal Edema
Swelling of the cornea — whether from conditions such as Fuchs' endothelial dystrophy or following eye surgery — causes fluid to accumulate in the corneal tissue, scattering incoming light and producing halos. Symptoms are often worse in the morning, when fluid that has built up overnight has not yet dispersed.
Post-Surgical Changes
Halos and glare are a recognised side effect following LASIK and PRK laser eye surgery, particularly during the early healing period. They result from corneal reshaping and changes in the ratio of the pupil size to the treatment zone. For most people, these symptoms reduce substantially within weeks to months as the cornea heals.
Noticing halos around lights or persistent glare? It's worth getting a professional eye test to identify the cause early. Book online at your nearest Eye Concepts location.
Symptoms to Be Aware Of
Halos and glare often appear alongside other visual symptoms. Being able to describe these accurately to your optometrist helps narrow down the most likely cause:
Rings or circles of light around streetlights, headlights, or indoor light sources
Starburst patterns radiating from light sources (particularly common with astigmatism)
Reduced contrast or washed-out vision in bright conditions
Difficulty driving safely at night due to glare from oncoming vehicles
Increased sensitivity to light (photophobia)
Eye strain or discomfort in brightly lit environments
Fluctuating visual clarity throughout the day (a hallmark symptom of dry eye disease)
Ghost images or double vision from a single eye
If halos or glare develop suddenly, worsen noticeably, or are accompanied by eye pain or reduced visual acuity, an assessment with an AHPRA-registered optometrist should be prioritised.
How Are Halos and Glare Managed?
Management depends entirely on the underlying cause, which is why an accurate diagnosis is the essential starting point. The following approaches may be recommended following a comprehensive eye examination.
Corrective Lenses and Updated Prescriptions
For halos linked to uncorrected refractive errors, including astigmatism halos around lights, updating your spectacle or contact lens prescription is often the most effective first step. Anti-reflective coatings on spectacle lenses reduce surface reflections and can improve night-time glare noticeably. Polarised lenses are particularly effective at managing glare from reflective outdoor surfaces such as wet roads or water.
Dry Eye Management
If dry eye disease is contributing to halos and glare, lubricating eye drops or prescribed dry eye therapies may help reduce the severity of symptoms. An optometrist can assess tear film quality and quantity using in-chair tests and recommend an appropriate management plan, which may include heat and massage therapy, prescription eye drops, or dietary adjustments.
Managing Underlying Eye Conditions
Conditions such as cataracts, keratoconus, glaucoma, and corneal oedema each have specific treatment pathways. These are best assessed and managed by an AHPRA-registered optometrist or ophthalmologist who can examine the eye structures directly and refer for surgical treatment where indicated. The appropriate management pathway depends on the underlying cause and is best determined following a thorough clinical assessment.
Lifestyle and Environmental Adjustments
Practical steps can help reduce the day-to-day impact of halos and glare:
Dim screen brightness and enable night mode on digital devices in the evening
Use dimmable lighting indoors where possible to reduce discomfort glare
Wear quality sunglasses with polarised or anti-reflective lenses when outdoors
Limit night driving if halos or glare are affecting your safety or confidence
Schedule regular eye examinations to monitor any changes in your vision
Frequently Asked Questions About Halos Around Lights and Glare
What causes halos around lights at night?
Halos around lights at night are most commonly caused by refractive errors such as astigmatism, where the irregular shape of the cornea or lens scatters light rather than focusing it precisely onto the retina. Other causes include cataracts, dry eye disease, keratoconus, and post-surgical corneal changes. Pupils also dilate in low light, which can exacerbate light scattering and make halos more visible at night.
What is glare, and why does it affect vision?
Glare is excessive brightness within the field of vision that overwhelms the eye's ability to adapt, reducing contrast and making it harder to distinguish detail clearly. It can be caused by external factors such as sunlight or oncoming headlights or by internal factors such as cataracts or dry eye disease that cause light to scatter before it reaches the retina
Do astigmatism halos around lights improve with glasses?
In many cases, yes. Astigmatism halos around lights result from irregular light focusing—corrective lenses that address the astigmatism can significantly reduce or resolve the halo effect. Anti-reflective coatings on spectacle lenses can further help by minimising surface reflections that contribute to glare at night. An up-to-date prescription is often the first thing to check if halos around lights are a concern.
Halos and glare can manifest with several common symptoms that affect visual comfort and performance. These symptoms often become more pronounced in bright or low-light conditions.
When should I see an optometrist about halos and glare?
You should book an eye examination if halos or glare appear suddenly, are getting progressively worse, affect your ability to drive safely at night, or are accompanied by other symptoms such as eye pain, headache, or reduced sharpness of vision. A sudden onset of halos combined with eye pain can indicate acute angle-closure glaucoma, which requires urgent assessment.
Can dry eyes cause halos around lights?
Yes. Dry eye disease disrupts the tear film that forms the smooth optical surface of the eye. A compromised tear film causes light to scatter unevenly as it enters the eye, producing halos, particularly at night, and increased glare sensitivity. Treating the underlying dry eye with lubricating drops or prescribed therapy often helps reduce these visual symptoms.
Are halos after LASIK or PRK surgery permanent?
Halos following LASIK and PRK are common in the early post-operative period as the cornea heals. For the majority of people, they reduce substantially over weeks to months. In a small number of cases they may persist, particularly if the treatment zone does not adequately cover the pupil in dim lighting conditions. An optometrist can assess whether any follow-up management is appropriate.
Book an Eye Examination at Eye Concepts
If you've noticed halos around lights, increased glare, or any changes to your night-time vision, it's worth having your eyes assessed by an AHPRA-registered optometrist. Eye Concepts offers comprehensive eye examinations to identify the cause of visual disturbances and guide you through the appropriate next steps.