Are Halos Around Lights a Sign of Cataracts?
Have you noticed rings around streetlights, a glowing haze around headlights, or unusual glare when driving at night? If lights seem to have halos around them, your eyes may be telling you something about your vision.
Yes, seeing halos around lights can be a sign of cataracts. Cataracts cause the eye's natural lens to become cloudy, scattering light instead of allowing it to pass through clearly. This can make headlights, streetlights, and other bright sources appear to have halos or glare around them.
However, cataracts aren't the only possible cause. Changes in your glasses prescription, astigmatism, dry eye, and certain eye conditions can also affect how you see lights.
Understanding what causes these changes can help you determine when it's time to schedule an eye exam.
How Do Cataracts Cause Halos Around Lights?
A cataract develops when the normally clear lens inside your eye becomes cloudy. The lens helps focus light onto the retina, which sends visual information to your brain.
As the lens becomes cloudy, light can scatter as it passes through the eye. Instead of seeing a headlight or streetlight as a clear point of light, you may notice a glowing ring, haze, glare, or starburst effect.
These symptoms may be more noticeable at night because your pupils naturally dilate in dim lighting, and bright lights stand out against a darker background.
Cataracts can also cause other vision changes, including:
- Blurry or cloudy vision
- Increased sensitivity to bright light
- Difficulty seeing clearly at night
- Trouble driving because of oncoming headlights
- Faded or yellowish-looking colors
- Double or ghosted images in one eye
Cataracts often develop gradually, so you might initially attribute these changes to aging, tired eyes, or a need for a new glasses prescription.
Noticing Halos Around Lights?
Halos can have several causes, including cataracts and other eye conditions. An eye evaluation can help identify what's affecting your vision and determine the right next steps.
Are Halos Around Lights Always a Sign of Cataracts?
No. Halos around lights can have several causes, and the appearance of the halos alone isn't enough to determine what's happening.
Other possible causes include:
1. Astigmatism and Other Refractive Errors
Astigmatism occurs when the cornea or lens has an irregular shape, affecting how light focuses inside the eye. This can cause blurred vision, glare, or starburst patterns around lights, particularly at night.
Nearsightedness and other refractive errors can also contribute to poor nighttime vision. An updated glasses or contact lens prescription may help if a refractive error is responsible.
2. Dry Eye
Your tears help create a smooth optical surface over your eyes. When the tear film is unstable, light may not focus as clearly, resulting in fluctuating blur, glare, or halos.
Dry eye may also cause burning, irritation, a gritty sensation, or redness. An ophthalmologist can help determine whether dry eye is contributing to your symptoms.
3. Glaucoma
Certain forms of glaucoma can cause halos, particularly acute angle-closure glaucoma. This condition occurs when the drainage pathway inside the eye becomes blocked, causing eye pressure to rise rapidly.
Sudden halos accompanied by severe eye pain, a red eye, blurred vision, headache, nausea, or vomiting require immediate emergency evaluation. Acute angle-closure glaucoma can threaten vision and should not wait for a routine appointment.
Not all glaucoma causes noticeable symptoms in its early stages, which is one reason regular comprehensive eye exams are important.
4. Changes After LASIK or Cataract Surgery
Some people experience glare, halos, or starbursts after refractive surgery or cataract surgery. These symptoms can be more noticeable at night and may improve as the eyes heal, depending on the cause.
Persistent or worsening symptoms deserve an eye examination, particularly if they interfere with driving or daily activities.
Why Are Halos Around Lights More Noticeable at Night?
Nighttime halos can be especially frustrating because they may affect your ability to drive comfortably and confidently.
There are a few reasons this happens:
- Dim lighting: Your pupils widen in the dark, allowing more light into the eye.
- Bright headlights: The contrast between bright headlights and a dark road can make glare more noticeable.
- Changes in the eye's lens: Cataracts can scatter light, reducing contrast and making nighttime vision more difficult.
- Uncorrected vision problems: Astigmatism and other refractive errors can contribute to glare and distorted light patterns.
If you regularly struggle to see road signs, judge distances, or tolerate oncoming headlights, don't ignore the problem. Avoid driving at night if your vision is not safe for driving, and arrange an eye examination to identify the cause.
How Can You Tell if Cataracts Are Causing Your Halos?
You cannot reliably diagnose cataracts based on halos alone. An ophthalmologist will evaluate your symptoms and examine your eyes to identify the underlying cause.
Your examination may include:
- Visual acuity testing: Measures how clearly you can see at different distances.
- Refraction testing: Checks whether glasses or contact lenses can improve your vision.
- Slit-lamp examination: Allows the ophthalmologist to examine the front structures of your eye, including the natural lens, for signs of cataracts.
- Dilated eye examination: Helps assess the lens, retina, optic nerve, and other structures inside the eye.
- Eye pressure measurement: Helps evaluate your risk for certain forms of glaucoma.
The appropriate tests depend on your symptoms and examination findings. The goal is to determine whether cataracts are responsible or whether another eye condition needs treatment.
A must read: Should I Get LASIK? 7 Signs You’re Ready for Laser Vision Correction
Can Cataract Surgery Get Rid of Halos Around Lights?
If cataracts are causing your halos, cataract surgery may improve your vision and reduce cataract-related glare.
During cataract surgery, the surgeon removes the cloudy natural lens and replaces it with an artificial intraocular lens (IOL). The procedure can improve visual clarity when cataracts interfere with everyday activities, including reading, working, and driving.
However, cataract surgery does not guarantee that all halos or glare will disappear. Your results depend on the cause of your symptoms, the health of your eyes, and other factors. Some patients experience halos or other visual disturbances after surgery, particularly with certain lens designs.
An ophthalmologist can assess your eyes, discuss your visual goals, and explain which treatment options may be appropriate.
You don't necessarily need cataract surgery as soon as a cataract is identified. Surgery is generally considered when the cataract significantly affects your vision or quality of life and the expected benefits outweigh the risks.
When Should You See an Ophthalmologist for Halos Around Lights?
Schedule a comprehensive eye examination if you notice persistent or worsening halos, increasing nighttime glare, blurry vision, or difficulty performing everyday activities.
Seek emergency medical care immediately if halos begin suddenly with severe eye pain, redness, a headache, nausea, vomiting, or sudden blurred vision. These symptoms may indicate acute angle-closure glaucoma or another serious eye problem.
New or sudden vision changes should not automatically be attributed to cataracts or aging.
Get Answers About Your Vision at MiVision Eye Care
Seeing halos around lights can be frustrating, especially when nighttime driving becomes more difficult. Although cataracts are one possible cause, a thorough eye examination is the best way to determine what's affecting your vision.
At MiVision Eye Care, Dr. Melanie Mihlstin provides ophthalmology care in Saginaw, Michigan, including cataract evaluation and treatment. Our team can help assess your symptoms, explain your findings, and discuss appropriate next steps based on your eye health and visual needs.
If you've noticed halos around lights or changes in your nighttime vision, contact MiVision Eye Care to inquire about an appointment. You don't have to wait until your vision becomes severely impaired to ask about changes you're experiencing.
Your vision deserves careful attention.