What Causes Halos Around Lights?

It is not uncommon that people report seeing bright circles when they look directly at light sources, such as headlights or lamps, especially at night. Sometimes they are harmless and just a typical response from the eye or may even be simply a result of wearing glasses or contact lenses. However, these halos can also be a red flag, especially when other symptoms happen at the same time. They could be a side effect of other diseases, such as cataracts.

halos around lights

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Causes

Seeing halos around lights is a result of diffraction, an effect that occurs when the light bends while entering the eye. Diffraction can sometimes be caused by glasses and contact lenses, but it can also be a disease's side effect.

The causes of halos around lights include:

  • Cataracts: Seeing halos is one of the most common symptoms of cataracts, especially in posterior subcapsular cataracts. This type of cataract causes light sensitivity, blurred near vision, and glare and halos around lights. It is more common among people who have diabetes or who have been taking steroids for extended periods of time
  • Dry eye syndrome: It is not uncommon that the eye's superficial part becomes irregular when it is too dry. The unusual shape will often affect how the eye receives light and, as a result, the person starts seeing halos around bright spots. Dry eye can also cause redness, burning, pain, and stinging 
  • Fuchs' dystrophy: This disease makes the cornea swell, causing the light to bend when entering the eye. It is a hereditary, progressive disease of the posterior cornea, which results in excrescences of the Descemet membrane, endothelial cell loss, corneal edema, and, in late stages, bullous keratopathy.  It is more common in people 50 years old or over
  • Nearsightedness and farsightedness: The retina is fragile and is located on the back of the eye. Conditions that affect this sensitive area can make a person see halos. Nearsightedness and farsightedness are two of them
  • Astigmatism: It happens when the cornea or lens has an irregular curvature. Therefore, light doesn't spread evenly on the retina, which can result in halos

When to See a Doctor

Although many people believe that seeing halos around bright lights is not a problem, it is always good to make an appointment for an eye exam with an optometrist or ophthalmologist to have your eyes checked out even if you don't have any other symptoms. It is the only way to be sure that the halos you are seeing are harmless. 

Symptoms like blurred vision, eye pain, weak night vision, blind spot, dry, red, and itchy eyes are red flags. If you experience any of these symptoms, you should schedule an appointment as soon as possible.

Treatment

Treatment is needed for halos around lights that are caused by an underlying condition. The most common way to treat cataracts is with surgery, where the cloudy natural lens is removed and replaced with a clear artificial lens. Although it is not an emergency treatment, the surgery will prevent vision loss.

Artificial tears are the most popular treatment for dry eyes. They help lubricate the area. Doctors can also prescribe gels, ointments, oral or topical steroids. In some cases, punctal plugs may be recommended. 

The treatment for Fuchs’ dystrophy depends on how the condition affects your eye’s cells. In the early stages, the treatment consists of removing the eye's fluid with a sodium chloride solution or ointment. In advanced stages, a cornea transplant can restore the vision.

Nearsightedness and farsightedness conditions are often treated with corrective lenses. Doctors may also recommend refractive surgery in some cases. This procedure will reshape the cornea, and the light will enter the eye evenly. 

The treatment for astigmatism is similar to that for nearsightedness and farsightedness. The most common way to fix it is with glasses or contact lenses. Surgery can also be an efficient way to fix it.

A Word From Verywell

People should not underestimate sudden changes in their vision. Seeing halos around lights is not a disease, but it can be the first sign that something is not well with your eyes. Therefore, the wisest decision is to schedule an appointment with an eye care professional as soon as possible. If a medical condition is causing these halos, this can help you get it diagnosed treated early. 

Some daily habits can help to prevent eye diseases. Wearing sunglasses and hats to avoid ultraviolet radiation is one of them. A healthy diet rich in vitamins and carotenoids and avoiding alcohol and cigarettes are crucial to keeping your vision healthy. People who have diabetes should pay extra attention to their eyes and control their blood sugar levels.

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4 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Verywell. What Are Cataracts? March 30, 2020

  2. Eghrari AO, Riazuddin SA, Gottsch JD. Fuchs corneal dystrophy. Prog Mol Biol Transl Sci. 2015;134:79-97.

  3. American Academy of Ophthalmology. Cataract surgery.

  4. American Academy of Ophthalmology. Fuchs’ dystrophy treatment.

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