A potential side effect after LASIK is to see halos or glare, particularly around lights at night. You may also see starbursts, a type of glow that shoots out from a bright light.
These spherical aberrations usually fade after several weeks. In some cases, they may appear up to a year or more after the surgery.
What Are Halos & Glare?
While a halo is a bright circle of light that seems to surround a lighting source, glare is a form of illumination that interferes with your eyesight. For example, you might see halos when you view oncoming headlights, while glare can happen from an event like a camera flash.
How Common Are They After LASIK?
Both are fairly common following LASIK, particularly in the early healing stages.
Research shows that both the “aberrations” regularly appear, although they are not usually severe. One study evaluated halos and glare preoperatively and postoperatively, proving the phenomena were common, both before and after LASIK. For most people, their night vision improved after LASIK.
Why Do Halos & Glare Happen After LASIK?
When LASIK is performed, the surgeon cuts a flap in the upper part of the cornea. This part is known as the epithelium. The doctor lifts the flap, so they can adjust the shape of the cornea using a laser. After the cornea is reshaped, the surgeon places the flap back down.
Your eyes have to heal after LASIK, and this healing process involves swelling, or fluid accumulation. Halos may appear as this good fluid accumulates in the cornea. As the eyes heal, the fluid will drain and halos become less apparent.
When Do Halos & Glare Fade?
You’ll usually experience halos and glare for about two or three weeks following LASIK. However, they may last a month or longer in some cases.
Halos and glare typically begin to dim after the first week of recovery. You need to tell your doctor if the halos or glare are not subsiding somewhat after seven days.
Other Side Effects
Dry eyes may be another side effect LASIK patients experience after surgery. To minimize the condition, your eye doctor may give your eye drops or artificial tears.
Like halos and glare, this side effect is generally temporary, and most cases resolve within a couple months. It’s rare that patients still experience dry eyes six months after the surgery.
Treatment & Prevention
Advanced technology reduces the likelihood of experiencing halos, glare, and other side effects after LASIK. Today, complications and even side effects from LASIK are rare.
By using a laser to preserve the asphericity of the cornea, patients with large pupils, who are more susceptible for glare or halos, experience improved results. Asphericity represents the shape of a refractive medium and how it influences the bending of light.
As a result, it is important to review your surgical treatment during your pre-surgery assessment to see if you’re at a higher risk for experiencing glare or halos long term.
Other Causes for Halos & Glare
While halos usually appear in low-light conditions, glare usually appears during the daytime. Some people have more trouble focusing in bright light, which may also be a normal response in people more sensitive to light.
Cataracts can also cause problems with light sensitivity or glare. UV damage and the buildup of proteins in the eye causes the lens to get cloudy. As a result, cataracts develop over time. When this happens, the cataracts scatter light, blurring the images you’re seeing.
People with higher prescription lenses may experience more problems with halos or glare.
Dry eye may also trigger spherical aberrations or problems with light sensitivity. To combat the problem, an eye doctor may recommend eye drops to lubricate and moisten the eyes.
Tips for Reducing Problems With Halos & Glare After LASIK
Follow these steps to reduce any potential problems after LASIK:
- Customized treatment: A tailored approach helps to reduce problems with halos and glare. The degree of refractive error and pupil size both affect surgical outcomes. Therefore, researchers have found that optical modeling can improve postoperative results by enhancing surgical approaches and treatment plans.
Customization also extends to treatment, using a femtosecond laser. This laser adds to the precision of the procedure, helping to improve accuracy and reduce issues.
- Preoperative testing: Pre-surgical testing and exams give eye surgeons more details about the traits and characteristics of the eye. These exams cover the degree of correction needed, pupil size, and corneal thickness, among other things.
Your surgery will be based on the results of these tests. Better testing and measurements today results in better long-term outcomes from LASIK with fewer side effects and complications.
The Bottom Line
While halos can sometimes occur following LASIK, they are generally temporary, clearing within a couple months of the procedure. If you experience persistent halos, talk to your eye surgeon.
Also, make sure to discuss this potential issue with your surgeon before your procedure. Some individuals may be more at risk for this side effect.
Incidence of Glare, Halos, and Difficulty With Night Vision in Patients Undergoing Laser in Situ Keratomileusis. (December 2022). Investigative Ophthalmology & Visual Science.
Aspheric Benefits. (November 2006). Ophthalmology Times Europe.
[Aspheric Ablation for the Correction of Myopia: Clinical Results After LASIK With a Bausch & Lomb 217 Z 100 Excimer Laser]. (February 2009). National Center for Biotechnology Information.
What Is the Relevance of Asphericity in Today’s Ophthalmic Practice? (January-June 2011). Philippine Journal of Ophthalmology.
Benefits of Topography-Guided Treatments for Irregular Corneas. (June 2021). Ophthalmology Times.
Customized Eye Modeling for Optical Quality Assessment in Myopic Femto-LASIK Surgery. (August 2021). National Center for Biotechnology Information.
Theoretical Analysis of the Effect of Pupil Size, Initial Myopic Level, and Optical Zone on Quality of Vision After Corneal Refractive Surgery. (December 2012). Journal of Refractive Surgery.
Last Updated February 2, 2023
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