Why You See Halos Around Lights at Night (and When to Worry)
You’re driving home after dark, and suddenly the streetlights seem to have glowing rings around them. Or maybe you’ve noticed that oncoming headlights look like they’re surrounded by starbursts. If you’ve experienced halos around lights at night, you’re not alone—and you’re right to wonder what’s causing them.
At Looking Glass Optical in Pasadena, Maryland, Dr. Teles and Dr. Maner understand that changes in your night vision can be unsettling. The good news is that halos around lights aren’t always a sign of something serious. But they can be your eyes’ way of telling you that something needs attention. Let’s talk about what causes these halos, when they’re normal, and when it’s time to schedule an appointment.
What Are Halos Around Lights?
Halos are bright circles or rings that appear around light sources, particularly at night. They’re most noticeable around streetlights, car headlights, and other bright lights in dark environments. Some people describe them as glowing rings, while others see more of a starburst or radiating pattern.
These visual phenomena occur when light doesn’t focus properly on your retina. Instead of traveling straight through your eye’s optical system, the light scatters or bends in ways it shouldn’t. This scattering creates the halo effect you see.
Common Causes of Halos Around Lights
Understanding what’s behind those halos can help you determine whether you need to take action. Here are the most common culprits:
Refractive Errors
Sometimes, halos are simply a sign that your prescription needs updating. Nearsightedness, farsightedness, and astigmatism can all cause light to scatter as it enters your eye, creating halos around bright lights. This is especially noticeable at night when your pupils dilate and let in more light.
If you’ve been putting off that eye exam, and halos are your only symptom, you might just need new glasses or contact lenses. It’s one of the more straightforward explanations, and one of the easiest to fix.
Cataracts
Cataracts are one of the most common causes of halos, particularly in people over 60. As cataracts develop, the normally clear lens of your eye becomes cloudy. This cloudiness scatters incoming light, creating halos around light sources.
Other signs that cataracts might be the culprit include:
- Colors appear faded or yellowed
- Increased sensitivity to glare
- Difficulty seeing at night
- The need for brighter light when reading
- Frequent changes in your eyeglass prescription
Cataracts develop gradually, so you might not notice the changes right away. Many people adapt to slowly worsening vision without realizing how much their sight has changed. If you’re experiencing halos along with any of these other symptoms, it’s time to schedule a comprehensive eye exam.
Glaucoma
While less common than cataracts, glaucoma is a more urgent concern. This condition involves increased pressure inside your eye, which can damage the optic nerve and lead to vision loss if left untreated.
Halos around lights can be an early warning sign of acute angle-closure glaucoma, a medical emergency that requires immediate attention. If you experience halos accompanied by:
- Severe eye pain
- Sudden vision changes
- Nausea or vomiting
- Eye redness
- Intense headache
Don’t wait. Seek emergency medical care immediately. Acute angle-closure glaucoma can cause permanent vision loss within hours if not treated promptly.
Chronic glaucoma, which develops more slowly, can also cause halos but typically comes with fewer dramatic symptoms. Regular eye exams are crucial for catching this condition early, before it causes significant damage.
Dry Eyes
Your tear film does more than keep your eyes comfortable. It plays a crucial role in how you see. When your eyes don’t produce enough tears or the tears evaporate too quickly, the surface of your eye becomes irregular. This irregular surface can scatter light, creating halos, particularly at night.
Dry eye symptoms often include:
- A gritty or sandy feeling in your eyes
- Excessive tearing (as your eyes try to compensate)
- Burning or stinging sensations
- Blurred vision that improves with blinking
- Eye fatigue
Many people don’t realize their halos are related to dry eyes until they address the dryness and notice the halos improving. This is especially common during Maryland’s dry winter months when indoor heating systems reduce humidity.
Corneal Swelling (Corneal Edema)
Your cornea, the clear front surface of your eye, needs to maintain a specific level of hydration to function properly. When fluid builds up in the cornea, causing it to swell, light can’t pass through clearly. This can create halos and cause blurred or hazy vision.
Corneal swelling can result from various causes, including eye injuries, certain eye surgeries, infections, or conditions such as Fuchs’ dystrophy. If you wake up with particularly bad halos that improve as the day goes on, corneal swelling might be the cause.
Larger Pupils
Some people naturally have larger pupils, and this can become more apparent at night when pupils dilate in low light conditions. Larger pupils allow more peripheral light rays to enter the eye, and these outer rays are more likely to be imperfectly focused, creating halos.
While this is often just a normal variation, it’s worth mentioning to your eye doctor, especially if the halos are bothersome or seem to be getting worse.
Medications
Certain medications can affect your vision, causing halos around lights. These include some medicines for high blood pressure, anxiety, and other conditions. If you’ve recently started a new medication and noticed halos appearing, mention this to both your prescribing doctor and your eye care professional.
When Halos Are Normal
Not every halo is cause for concern. There are some situations where seeing halos is perfectly normal:
- Bright Lights in Dark Environments: Almost everyone will see some degree of halo around very bright lights in very dark conditions. This is how our eyes handle extreme contrasts in light.
- After Rubbing Your Eyes: If you’ve just rubbed your eyes, you might temporarily see halos due to the distortion of your tear film. These should disappear within a few moments.
- When You’re Tired: Fatigue can affect your vision in various ways, including causing temporary halos. If halos only appear when you’re exhausted and disappear after rest, they’re probably not a concern.
- Dusty or Dirty Glasses: Sometimes the problem isn’t your eyes at all, it’s your lenses. Smudged or dusty glasses can scatter light, creating halo effects.
When To See A Doctor
So, how do you know when halos warrant a visit to Looking Glass Optical? Here are the situations that deserve professional attention:
- Halos That Persist or Worsen: If you’re seeing halos consistently, or if they’re becoming more pronounced over time, don’t ignore them. This suggests an underlying issue that needs evaluation.
- Halos with Other Symptoms: Any halos accompanied by pain, redness, sudden vision changes, or other concerning symptoms should be checked promptly.
- Halos That Affect Your Daily Life: If halos are making it difficult or unsafe for you to drive at night, or if they’re interfering with your everyday activities, it’s time for an exam.
- New Halos: If you’ve never experienced halos before and they suddenly appear, get your eyes checked. New symptoms often indicate changes that need professional evaluation.
- You’re Over 60: Even if your halos don’t seem severe, it’s worth having them evaluated if you’re in the age range where cataracts commonly develop.
- You Have Risk Factors: If you have a family history of glaucoma, diabetes, or other conditions that affect eye health, be proactive about any vision changes.
Living with Halos
While you’re working with your eye doctor to address the underlying cause of halos, some strategies can help you manage:
- For Driving: Reduce speed at night, increase following distance, and keep your windshield meticulously clean. Consider avoiding night driving if halos make it unsafe.
- Reduce Glare: Anti-reflective coating on your glasses can significantly reduce halos and glare, especially at night.
- Manage Dry Eyes: Use preservative-free artificial tears regularly, especially if dry eyes are contributing to your halos. Or look into IPL Therapy for long-term results.
- Optimize Lighting: Avoid looking directly at bright lights when possible, and use dimmer switches at home to reduce contrast between light sources and surrounding darkness.
- Stay Current with Prescriptions: Make sure your glasses or contact lenses are up to date. Even small prescription changes can make a difference in how many halos you experience.
The Bottom Line
Halos around lights at night are your eyes’ way of communicating. Sometimes they’re saying, “You need new glasses.” Other times, they’re an early warning sign of something more significant, like cataracts or glaucoma. The key is not to ignore them.
At Looking Glass Optical, we’ve seen countless patients who waited too long to address their halos, thinking they were just a regular part of aging or something they had to live with. But here’s the truth: you don’t have to accept compromised vision. Whether your halos are caused by something simple or something that requires treatment, identifying the cause is the first step toward clearer, more comfortable vision.
If you’re seeing halos around lights, especially if they’re new or worsening and affecting your daily activities, don’t hesitate to reach out. Dr. Teles and Dr. Maner are here to help you understand what’s happening with your eyes and guide you toward the best solution. Your vision is too important to leave to chance, and those halos might be telling you something important.
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