Halos and glare at night after refractive surgery
Seeing halos around headlights or being dazzled by lights at night is among the visual effects sometimes experienced after refractive surgery. These phenomena, often temporary, can be surprising in the first few weeks, especially when driving in the evening. Understanding why they appear, how they evolve and when to seek advice helps you approach this period with greater peace of mind.
Quick answer: an often temporary phenomenon
Key point. Night-time halos and glare correspond to the perception of bright rings or scattered light around vivid light sources, especially in the dark when the pupil dilates. After refractive surgery, they are explained by the optical changes in the cornea or by the treatment zone in relation to the diameter of the pupil. In most cases, they are more pronounced in the first few weeks and then fade as the eye heals and the brain adapts. Certain factors, such as a large pupil or a strong correction, can intensify them. A delayed onset or a worsening should prompt you to seek advice.
Halos, glare, starbursts: what are we talking about?
These terms describe related but distinct perceptions, grouped together under the name night-time light phenomena (or dysphotopsia). Telling them apart helps you better describe your discomfort during follow-up:
- Halos: bright circles or rings that surround a light source, typically headlights or street lamps.
- Glare: a sensation of discomfort when facing a bright light, which can momentarily reduce visual comfort.
- Starbursts: rays or spikes of light that seem to radiate from a point of light, like a star.
All three are more visible in the dark, when the pupil is dilated, and can occur with both refractive surgery and cataract surgery. Describing them precisely to your ophthalmologist helps them assess their origin and how they evolve.
Why do these halos appear?
At night, the pupil dilates to let in more light. It can then “spill over” beyond the optical zone treated by the laser or beyond an implant’s optic, at the junction between the corrected part and the rest. Light that passes through this transition zone scatters and creates the sensation of a halo or glare. Higher-order optical aberrations, which measure the fine imperfections in the path of light through the eye, also play a role. The larger the pupil and the stronger the correction, the more these effects can show up at first.
How do they evolve over time?
In most cases, halos are more present in the first few weeks, then gradually diminish. Two mechanisms contribute to this: the healing of the eye, which regularises the optics, and neuro-adaptation, the process by which the brain learns to filter out these stray signals. Over the months, night-time discomfort most often becomes faint and does not get in the way of everyday activities. A minority of people retain a more lasting sensitivity, which is discussed during follow-up.
Do these symptoms depend on the technique?
All correction techniques can be accompanied by light phenomena at the start, but their intensity depends above all on parameters specific to each eye: the diameter of the pupil at night, the extent of the correction and the size of the optical zone treated. LASIK, PRK and SMILE reshape the curvature of the cornea; current treatment profiles and enlarged optical zones aim to reduce these effects compared with older generations of lasers.
With a phakic implant (ICL) or a cataract implant, halos can also be perceived, in connection with the implant’s optic. In all cases, the preoperative analysis of the pupil and the correction makes it possible to anticipate the risk and to adapt the choice of technique to your eye.
How can you limit the discomfort day to day?
- Patience: giving the eye time to heal and the brain time to adapt during the first few weeks.
- Caution when driving at night: adapting your driving while night vision has not stabilised, especially at the start.
- Follow-up: reporting the discomfort to your ophthalmologist, who checks the healing and suggests solutions if needed.
- Prevention: the preoperative assessment measures the pupil and the correction, parameters taken into account to reduce the risk of halos.
Measuring the size of the pupil is one of the elements analysed during the preoperative assessment, precisely in order to anticipate this kind of symptom and choose parameters suited to your eye.
FAQ
Frequently asked questions
Do halos after refractive surgery go away?
Most often, they fade markedly over the weeks and months, thanks to healing and the brain’s adaptation. More lasting discomfort is less common and is discussed during follow-up with your ophthalmologist.
Can I drive at night after the operation?
Resuming night driving depends on each person’s recovery. As long as night vision has not stabilised, it is sensible to adapt or limit driving in the evening. Your ophthalmologist guides you according to how you progress.
Why do I have more halos than other people?
Several factors come into play, in particular the size of your pupil at night and the extent of the correction. This is why these parameters are measured before the procedure in order to adapt the treatment.
When should I be concerned?
A delayed onset of halos, a worsening, a drop in vision or pain are not expected and warrant seeking advice promptly from your ophthalmologist.
Are halos dangerous for the eyes?
No, in themselves halos do not harm the eye: they are optical phenomena linked to the way light is perceived. They mainly affect night vision at the start. What should raise concern is pain, redness or an associated drop in vision, which warrants seeking advice.
Can glasses or a treatment help?
In some cases, your ophthalmologist may suggest measures to improve night-time comfort, such as suitable glasses or, more rarely, certain eye drops. These options are discussed on a case-by-case basis during follow-up, once healing has been assessed.
Can the preoperative assessment predict halos?
It does not predict them with certainty, but it identifies the risk factors, in particular a large pupil at night and a strong correction. These measurements make it possible to adapt the treatment parameters to limit the risk of halos.
Scientific sources
- Lim DH, Lyu IJ, Choi SH, Chung ES, Chung TY. Risk factors associated with night vision disturbances after phakic intraocular lens implantation. Am J Ophthalmol. 2014;157(1):135-141.e1. PMID 24182745.
- Li SM, Kang MT, Wang NL, Abariga SA. Wavefront excimer laser refractive surgery for adults with refractive errors. Cochrane Database Syst Rev. 2020;12(12):CD012687. PMID 33336797.
- Liu T, Lu G, Chen K, Kan Q. Visual and optical quality outcomes of SMILE and FS-LASIK for myopia in the very early phase after surgery. BMC Ophthalmol. 2019;19(1):88. PMID 30961593.
Further reading
Refractive assessment at the Cachan office · Tel. 01 45 47 08 11
Take stock of your night vision in Cachan
Persistent or bothersome halos deserve an evaluation. For an assessment before the procedure or a follow-up of your night vision, book an appointment with Dr Moïse Tourabaly. Laser refractive surgery is carried out at the Clinique Laser Victor Hugo, after a full assessment at the Cachan office.
In summary
Night-time halos and glare are common and most often temporary visual effects after refractive surgery: they are explained by the optical changes in the eye and the dilation of the pupil at night, and they fade as the cornea heals and the brain adapts. The preoperative assessment, by measuring the pupil and the correction, helps anticipate this risk.
The key takeaway: stay cautious when driving in the evening during the first few weeks, and seek advice without delay if halos appear late or worsen. Laser refractive surgery is carried out at the Clinique Laser Victor Hugo, after a full assessment at the Cachan office.
This article is intended for information and educational purposes. It is not a substitute for a medical consultation. Any persistent or unusual visual symptom after refractive surgery should be evaluated by your ophthalmologist. Sources: articles indexed on PubMed; recommendations of the French Society of Ophthalmology (SFO).
Written and reviewed by Dr Moïse Tourabaly, ophthalmic refractive surgeon — former chief resident (Quinze-Vingts National Eye Hospital).
Last updated: July 6, 2026
