Halos around lights are rings or glows seen especially at night or in dim conditions. They usually arise when light is scattered by the cornea, lens, or tear film rather than focusing cleanly.
Possible Causes
Common reasons include uncorrected refractive error, dry eye, and glare from cataract or early lens changes. More serious causes include corneal oedema from acute glaucoma or post‑surgical complications, and certain contact lens problems.
- Halos with eye pain, redness, and blurred vision can indicate acute angle‑closure glaucoma
- After refractive or cataract surgery, temporary halos may occur while the eye heals
- Dirty or scratched spectacle or contact lenses can exaggerate halo effects
- Irregular corneal conditions such as keratoconus may cause starbursts and halos
When to Seek Review
New, persistent, or markedly worsening halos, especially with other symptoms, should be assessed to exclude urgent disease. Routine assessment can identify treatable causes such as cataract or dry eye.
- Drivers noticing troublesome halos should arrange an eye check promptly
- Accurate spectacle or contact lens correction often reduces symptoms
- Report any associated headache, nausea, or coloured rings urgently
- Monitoring is important when medications or surgery may affect corneal clarity
