Introduction

Imagine stepping out into the night and being greeted not just by lights, but by luminous rings surrounding every lamp, headlight, or neon sign. For some, these halos might seem poetic — a dreamy filter over the world. But for others, especially those experiencing them more frequently or more intensely, they become a source of concern, discomfort, or even fear. At Jryn Eye Clinic in Busanjin-gu, Busan, we often meet patients who delayed seeking help, thinking, “It’s just part of getting older,” or “Maybe my glasses need cleaning.”

Light halos may indeed be harmless. But they can also signal deeper issues. That’s why understanding when to pay attention — and when to act — can make all the difference in your long-term vision health. In this article, we’ll explore the causes of halos, from the benign to the serious, and guide you on when it’s time to see an eye specialist.

What Are Light Halos, Really?

Halos are visual artifacts — circular glows or rings — that appear around bright light sources. Most often, people notice them at night, especially while driving or walking under street lamps. Technically speaking, halos are caused by the scattering of light as it enters the eye and hits the retina. Depending on what's going on inside your eye — whether it's the lens, the cornea, or even your tear film — that scattering can be minor or significant.

In ophthalmology, we often use the term "visual disturbances" to group these effects. Halos are one form of this disturbance, and they reflect how light is being manipulated (or misdirected) within the eye. While halos can simply be a natural quirk of the eye’s optics, they may also reflect something deeper, such as lens clouding, corneal irregularities, or pressure changes within the eye. The key is context: Are these halos new, persistent, or worsening? Do they come with other symptoms? Are they interfering with your daily activities, like driving at night or reading under bright light?

When Halos Are Nothing to Worry About

Not every light halo is a red flag. In fact, we often see patients who experience halos due to more benign — and fixable — issues:

• Outdated or incorrect glasses/contact lens prescriptions. A slight misalignment in your prescription can cause light to scatter inappropriately, especially in low-light environments. The eye relies on perfectly focused light for clarity, and any error in refraction can create glare or halo effects.
• Dry eyes. A surprisingly common culprit in Korea, particularly during the winter months or among office workers exposed to screen time and air conditioning. When the tear film is unstable, light refracts unevenly. Tear film instability can act like a bumpy road for light to travel across — instead of a smooth highway.
• Post-surgery effects. Patients who have recently undergone vision correction procedures like LASIK, SMILE, or ICL may experience temporary halos as the eye heals and adapts. This is especially true during the night when the pupil is more dilated, exposing parts of the cornea that weren’t affected during surgery.
• Environmental or lighting conditions. Humid weather, fog, or bright LED lighting can exaggerate the appearance of halos. Sometimes the issue isn’t with your eyes, but with how external light behaves before it even reaches you.

In these cases, the halos typically fade as your eyes stabilize — whether through updated eyewear, better dry eye management, or natural healing post-surgery. If you're unsure, a short follow-up with your eye doctor can provide clarity. One of the most rewarding things we see at Jryn Eye Clinic is a patient returning after dry eye treatment, saying, “I can finally drive at night without stress.”

But Sometimes, Halos Mean Something More Serious

This is where it becomes important not to self-diagnose. Halos — particularly when they’re sudden, persistent, or paired with other symptoms — can be early signs of more serious eye conditions.

• Cataracts. One of the most frequent causes we see in middle-aged and older adults. As the eye’s natural lens becomes cloudy, it disrupts how light is focused. Patients often report increased glare, difficulty driving at night, and halos around headlights — like looking through a foggy window. Cataracts develop slowly, but the visual effects can be disorienting and frustrating long before surgical treatment is required.
• Glaucoma, especially angle-closure type. This is a medical emergency. If you experience halos along with severe eye pain, nausea, vomiting, headache, or blurred vision, go to an eye clinic immediately. These could be signs of rapidly increasing intraocular pressure. At Jryn, we’ve treated patients who ignored these signs for a day too long — leading to preventable vision loss.
• Fuchs' Dystrophy or corneal edema. These corneal disorders cause swelling or water retention in the cornea, distorting incoming light. In Fuchs’ Dystrophy, the inner layer of corneal cells degenerates, impairing the cornea’s ability to stay clear. The first sign is often seeing halos in the morning that improve during the day.
• Keratoconus. A progressive thinning and bulging of the cornea that leads to distorted, irregular vision — often with halos, ghosting, and sensitivity to light. It typically begins in young adulthood, and early detection can allow for stabilization through treatments like corneal cross-linking.
• Other causes. From residual scarring after injury to chronic eye conditions like uveitis or even systemic diseases like diabetes, various health issues can manifest as light halos. Diabetes in particular, due to its effect on the eye’s vascular system and lens clarity, is a quiet contributor to changing light perception.

When to Book an Eye Exam — And What to Expect

So how do you know when it’s time to see a professional? If any of the following apply, we strongly recommend you schedule an eye exam:

• The halos have persisted for more than a few days or weeks.

• You’ve noticed them becoming more frequent or intense over time.

• Night driving has become difficult or dangerous due to glare.

• You experience halos along with headaches, nausea, or vision changes.

• You have a history of diabetes, high blood pressure, or eye surgeries.

• You’ve recently noticed rapid changes in your glasses prescription.

At Jryn Eye Clinic, our approach starts with listening. We conduct a thorough exam that includes:

• Refraction testing to check your vision and ensure your prescription is accurate.
• Slit-lamp examination to inspect the cornea, lens, and anterior chamber.
• Intraocular pressure measurement to screen for glaucoma.
• Corneal topography and OCT imaging, if structural issues are suspected.
• Tear film analysis to assess for dry eye syndrome.

Why We Care — A Perspective from Jryn Eye Clinic

Here in Busan, we often hear patients say, “I thought it was just my age,” or “I didn’t think it was worth checking.” But part of our mission at Jryn Eye Clinic is to shift that mindset. Vision is precious — and it’s not just about clarity, but quality of life. Being able to drive safely at night, enjoy a movie without glare, or read without discomfort isn’t a luxury. It’s your right.

We’ve treated patients as young as 25 and as old as 85 for halo-related concerns. Each one brought a unique story. Some were relieved to find it was just dry eyes. Others were grateful for the early detection of cataracts or pressure issues that could’ve gone unchecked. The common thread? Each patient left more informed, more confident, and more empowered to care for their eyes.

That’s why we advocate for regular eye exams, especially when symptoms like halos appear. Whether it turns out to be dry eyes or early cataracts, early detection allows for better outcomes and more treatment options. You don’t need to wait for symptoms to worsen. The earlier we catch the problem, the better your chances for long-term visual success.

Final Thoughts

If you’ve been noticing halos around lights — don’t ignore it. Your eyes may be trying to tell you something. While many causes are minor and manageable, others may signal the beginning of more serious conditions.

Think of light halos as your eye’s “check engine” light. Not always urgent, but never something to dismiss outright.

In Korea’s fast-paced lifestyle, it’s easy to overlook small changes in how we see. But taking the time to investigate these changes can have lasting benefits. Whether it’s preventing a glaucoma attack, planning timely cataract surgery, or simply updating your lenses, that first step — a proper eye exam — makes all the difference.

If you're in Busan or nearby and need expert evaluation, consider booking a consultation at Jryn Eye Clinic. With state-of-the-art diagnostics and a personalized, patient-first philosophy, we’re here to help you see clearly — now and into the future.