Vision Halos and Glare: What Is It, Causes, Symptoms, and Treatment

Vision halos and glare are common visual disturbances that affect many people. These can be a normal response to certain lighting conditions but may also be associated with underlying eye health issues.

We'll help you understand the causes, symptoms, and treatments for these disturbances to maintain good eye health and address any potential problems early on.

What Are Halos?

Halos are optical phenomena that appear as rings or circles of light around bright objects, such as headlights or streetlights. They are often more noticeable in low-light conditions, like at night, and can be described as bright circles, sometimes colourful, surrounding light sources.

Halos around lights occur due to the way light enters the eye, particularly when it is diffracted or bent.

What is Glare?

Glare is an intense light that impairs vision by reducing the ability to see clearly. It occurs when excessive brightness in the visual field overwhelms the eye, making it difficult to distinguish details and objects.

Types of Glare

Glare can be categorized into several types based on its causes and effects on vision. These types include Disability Glare, Discomfort Glare, Night Glare, Veiling Glare, and Photostress Glare.

1. Disability Glare

Disability Glare is a form of glare that directly impairs vision by reducing contrast and visibility. It occurs when light is scattered within the eye, which decreases the ability to distinguish objects. Common triggers include sunlight and car headlights, especially when driving towards them.

2. Discomfort Glare

Discomfort Glare is a psychological sensation caused by high-brightness contrast within the visual field. It does not necessarily impair vision but can cause eye strain and discomfort.

Artificial lighting sources like fluorescent lights or LED screens often trigger discomfort glare. The discomfort varies among individuals and depends on factors such as the luminance and position of the light source relative to the line of sight.

3. Night Glare

Night Glare is a specific type of glare that occurs at night due to pupillary dilation and increased sensitivity to artificial lights. It can cause difficulty driving and visual distortions, particularly from car headlights or neon signs.

4. Veiling Glare

Veiling Glare results from light diffusion across the retina, often caused by environmental factors like fog or smog, which reduces contrast and leads to washed-out images.

5. Photostress Glare

Photostress Glare occurs from sudden exposure to intense brightness, such as camera flashes, causing temporary visual impairment and afterimages.

What Causes Halos and Glare?

Halos and glare can be caused by various factors, including eye conditions, post-surgical effects, and environmental or behavioural triggers.

1. Eye Conditions That Cause Halos and Glare

Several eye conditions can lead to the appearance of halos and glare. These include:

• Cataracts: Clouding of the eye lens leads to light scattering and increased sensitivity to glare. Additional symptoms include blurred vision and reduced colour perception.

• Refractive Errors: Conditions like myopia (nearsightedness), hyperopia (farsightedness), and astigmatism can cause light to scatter, resulting in halos and glare. Astigmatism is particularly known for causing halos at night due to irregular corneal shape.

• Corneal Edema: Swelling of the cornea, often due to conditions like Fuchs' dystrophy, which causes fluid buildup and light scattering.

• Glaucoma: Elevated intraocular pressure can lead to sudden onset of halos, especially in acute angle-closure glaucoma.

• Keratoconus: It is where the cornea becomes thinner and cone-shaped, affecting light focus and causing halos.

• Photokeratitis: Temporary damage to the cornea from UV exposure, leading to halos and sensitivity to light.

• Dry Eyes: Insufficient tear production can cause light scattering, leading to halos, especially at night.

Here is a summary table of these conditions and their effects:

Condition	Halos	Glare	Additional Symptoms
Cataracts	Yes	Yes	Blurred vision, colour reduction
Refractive Errors	Yes	Yes	Blurred vision, eye strain
Corneal Edema	Yes	Yes	Swelling, blurred vision
Glaucoma	Yes	Yes	Eye pain, blurred vision
Keratoconus	Yes	Yes	Distorted vision
Photokeratitis	Yes	Yes	Eye pain, sensitivity to light
Dry Eyes	Yes	Yes	Eye irritation, discomfort

2. Post-Surgical Causes

Surgical procedures can also lead to temporary or persistent halos and glare:

• LASIK & PRK: Temporary halos and glare due to corneal healing and swelling.

• Cataract Surgery (IOL implants): Light diffraction from artificial lenses can cause halos and glare.

• Lens Replacement Surgery: Similar to cataract surgery, the new lens can cause glare and halos during the healing process

3. Environmental and Behavioral Triggers

Environmental and behavioural factors can exacerbate halos and glare:

• Night Driving: Headlights and streetlights can cause glare and halos, especially in low-light conditions.

• Digital Screen Exposure: Prolonged blue light exposure from screens may lead to discomfort and eye strain.

• Bright Indoor/Outdoor Lighting: Direct sunlight, LED lights, and other bright sources can cause glare and discomfort.

• Fog, Smog, or Pollution: Environmental conditions that scatter light, leading to veiling glare and halos.

• Camera Flashes: Sudden exposure to intense light can cause photo stress glare and temporary visual disturbances

Symptoms of Halos and Glare

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.

• Blurry Vision in Bright Settings: Both halos and glare can lead to blurred vision, especially when light sources are intense. This is because the scattered light or intense glare can interfere with the eye's ability to focus clearly.

• Increased Light Sensitivity (Photophobia): People experiencing halos and glare may find themselves more sensitive to light, which can cause discomfort and squint in bright environments.

• Difficulty Driving at Night: Halos around headlights and streetlights can significantly impair night driving by reducing visibility and increasing the risk of accidents. Glare from oncoming traffic can also exacerbate this difficulty.

• Eye Strain and Discomfort: Discomfort glare, in particular, can cause eye strain without necessarily impairing vision, leading to fatigue and discomfort during prolonged exposure to bright lights.

• Visual Distortions: In some cases, halos and glare can cause visual distortions, such as starbursts or streaks of light, which can further impair visual clarity.

How to Treat and Manage Halos and Glare

Managing halos and glare involves addressing the underlying causes and using various strategies to reduce their impact on vision. Treatment options range from lenses and glasses to corrective eye procedures, depending on the cause. Here are some effective ways to manage halos and glare:

1. Corrective Lenses & Glasses

Corrective lenses and glasses can significantly help manage halos and glare by improving light transmission and reducing reflections.

• Anti-reflective (AR) Coating Glasses: These reduce glare by minimizing reflections from the lens surfaces, improving visual clarity in bright conditions.

• Yellow-tinted Lenses for Night Driving: Yellow-tinted lenses can enhance contrast and reduce glare from oncoming cars' headlights, making night driving safer.

• Prescription Updates for Refractive Errors: Ensuring that prescriptions are up-to-date can help correct refractive errors like myopia, hyperopia, and astigmatism, which can contribute to halos and glare.

• Polarized Lenses: Polarized sunglasses are effective in reducing glare from reflective surfaces like water or car windshields.

• Blue Light Blocking Glasses: These can help reduce eye strain from digital screens, which may contribute to discomfort glare.

Here is a summary table of the best eyewear solutions for halos and glare:

Eyewear Solution	Benefits	Best Use	Helps Halos	Helps Glare
Anti-reflective (AR) Coating	Reduces glare from lens reflections	General use	✗	✓
Yellow-tinted Lenses	Enhances contrast, reduces night glare	Night driving	✓	✓
Prescription Updates	Corrects refractive errors	General vision correction	✓	✓
Polarized Lenses	Reduces glare from reflective surfaces	Outdoor activities	✗	✓
Blue Light Blocking Glasses	Reduces digital screen glare	Prolonged screen use	✗	✓

2. Medical and Surgical Treatments

Medical and surgical treatments are often necessary to address underlying conditions causing halos and glare. These interventions aim to correct the root cause and improve visual quality.

• Cataract Surgery: This procedure involves the replacement of a cloudy lens with an artificial intraocular lens (IOL), which can significantly reduce glare and halos caused by cataracts. However, some IOLs may still cause glare or halos, especially multifocal lenses.

• Corneal Cross-linking: This treatment is used for keratoconus, where the cornea has an irregular shape, leading to halos and glare. Corneal cross-linking strengthens the cornea and can reduce these symptoms.

• Eye Drops for Dry Eyes: Dry eyes can exacerbate glare due to insufficient tear production. Lubricating eye drops can maintain moisture and reduce glare.

• LASIK and PRK Adjustments: For patients experiencing halos after LASIK or PRK, adjustments or enhancements may be necessary to improve visual outcomes. This could involve additional laser treatments to enlarge the treatment zone or correct decentered treatments.

• Corneal Transplant: In severe cases of keratoconus or other corneal conditions, a corneal transplant may be required to restore clear vision and reduce halos.

3. Home Remedies and Lifestyle Adjustments

Some home remedies and lifestyle adjustments can also help manage halos and glare:

• Reduce Night Driving When Possible: Avoiding night driving can minimize the impact of glare and halos, especially if they are severe.

• Use Dimmable Indoor Lighting: Adjusting indoor lighting levels can reduce discomfort and glare caused by bright lights.

• Adjust Screen Brightness and Use Filters: Lowering screen brightness and using blue light filters can reduce eye strain and discomfort glare from digital devices.

• Wear Sunglasses: Using sunglasses with anti-reflective coatings or polarized lenses can help reduce glare during the day.

• Maintain Regular Eye Care: Regular eye exams are crucial for monitoring and addressing any underlying conditions that may be contributing to halos and glare.

When to See an Eye Specialist?

If you are experiencing halos and glare, it's important to know when these symptoms might indicate a serious issue requiring an eye care professional. Here are some guidelines:

• Sudden Appearance of Halos/Glare: If halos or glare suddenly appear, it could be a sign of acute conditions like angle-closure glaucoma, which is a medical emergency. Seek immediate care if accompanied by severe eye pain, headaches, nausea, or vomiting.

• Difficulty Driving at Night: If halos and glare make night driving unsafe, consult an eye specialist to assess your vision and address underlying conditions.

• Persistent Vision Issues: Persistent halos and glare may indicate serious conditions like cataracts or glaucoma. Regular eye exams aid in the early detection and management of these conditions.

Conclusion

Halos and glare are common visual disturbances that can be caused by normal responses to bright lights and underlying eye conditions like cataracts and glaucoma. Treatment options include corrective lenses, surgical interventions, and lifestyle adjustments.

If symptoms persist, consulting an eye specialist is essential for proper diagnosis and treatment. Regular eye exams help maintain optimal eye health and address any potential problems early on.