---
title: What causes rainbow halos around lights?
description: "Rainbow halos around lights can be harmless or signal serious eye pressure or corneal problems. ## Less serious causes Mild halos may occur with dry eye, dirty lenses, or early cataract. The effect often improves with blinking or cleaning. -…"
url: "https://bluefinvision.com/knowledge-base/topics/symptoms-signs/what-causes-rainbow-halos-around-lights/"
updated: "2025-12-31"
category: "Symptoms & Signs"
---

# What causes rainbow halos around lights?

Rainbow halos around lights can be harmless or signal serious eye pressure or corneal problems.

## Less serious causes

Mild halos may occur with dry eye, dirty lenses, or early cataract. The effect often improves with blinking or cleaning.

- Smearing on glasses or contact lenses
- Early lens clouding causing light scatter
- Minor corneal swelling from over-wear of contact lenses
- Temporary glare after bright light exposure

## Serious causes needing urgent care

Acute angle-closure glaucoma can cause intense pain and coloured haloes. This is an emergency needing immediate treatment.

- Haloes with severe eye pain, headache, and nausea
- Blurred vision and a hard, tender eye
- Redness and seeing rings around lights at night
- Emergency hospital assessment is essential to save sight