---
title: "When are flashes of light an emergency? | Eye Health Guide"
description: "New or repeated one-eye flashes can signal a retinal tear. How they differ from migraine zigzag, and who should skip this page."
url: https://eyehealthguide.org/answers/when-are-flashes-an-emergency/
source: Eye Health Guide
licence: "General information only. Cite the URL and the named medical reviewer."
---

Answer

# When are flashes of light an emergency?

Medical reviewer [Mr Mohamed Mohyudin](https://eyehealthguide.org/reviewers/mohamed-mohyudin/)· Last recorded site review July 6, 2026

### About this review

This page inherits the site’s previous review record. A separate, current article sign-off has not yet been recorded.

[How review works](https://eyehealthguide.org/reviewers/) · [Official biography & credentials](https://mohamedmohyudin.co.uk/author/mohamed-mohyudin/)

Quick answer

Flashes of light happen when the eye’s gel tugs on the retina. An occasional flash with long-standing floaters is often a PVD that still deserves a dilated check when it is new. Eye Health Guide advises same-day eye care for new or repeated flashes, a sudden shower of floaters, or any shadow across vision. Migraine zigzags in both eyes for minutes are a different pattern — new one-eye retinal-type flashes are not a reason to wait.

## Treat these as an emergency

- New or repeated flashes in one eye, especially with new floaters
- A sudden shower of spots
- A dark curtain or shadow spreading
- Sudden vision loss

### On this page ⌄

1. Treat these as an emergency
2. Who should skip this page?
3. How retinal flashes differ from migraine
4. What the examination is for
5. Read next
6. Frequently asked questions

## Who should skip this page?

If the red-flag list matches, go to emergency eye care rather than finishing the article. If you also have a sudden headache with weakness, speech change or a drooping face, call emergency services — that can be a stroke pattern, not only an eye-gel tug.

## How retinal flashes differ from migraine

Retinal flashes are often brief streaks or flickers in one eye, worse in the dark, and may come with floaters. Migraine visual aura is usually a binocular zigzag or scintillating scotoma that builds over minutes and then fades. The overlap can confuse people. New one-eye flashes still need a dilated retina check; do not self-diagnose migraine from this page.

Ocular migraine and retinal migraine are specialist labels. They do not cancel the rule that a curtain or a floater shower is an emergency.

[Ocular migraine](https://eyehealthguide.org/conditions/ocular-migraine/)[Floaters and flashes](https://eyehealthguide.org/conditions/floaters-and-flashes/)

## What the examination is for

The point is to find a retinal tear while it can still be sealed. Most new-flash patients have PVD without a tear. You cannot tell which group you are in from a description. Dilating drops and a look at the far periphery are the test; an undilated glance is not.

[Are eye floaters dangerous?](https://eyehealthguide.org/answers/are-eye-floaters-dangerous/)[Retinal tear](https://eyehealthguide.org/conditions/retinal-tear/)

## Read next

## Frequently asked questions

### I have had flashes for years. Is that an emergency?

Stable, occasional flashes that have not changed for a long time are often related to an old PVD. A new change in frequency, new floaters, or a shadow still needs same-day care.

### Can stress cause flashes?

Stress does not make a retinal tear safe to ignore. New one-eye flashes still need examination.

### Should I wait until morning?

Not if flashes are new and come with a floater shower or a curtain. Those cannot wait for a routine slot.

### Do both eyes flashing mean it is migraine?

Binocular zigzag that builds and fades over minutes often is migraine aura — still get checked if you are unsure, if it is a first episode, or if there are stroke symptoms.

Your next step

## Take this to your appointment

Write down what has changed, when it started, your current medicines and the questions you want answered. Take these to your eye-care appointment.

Sudden loss of sight, severe eye pain or a dark curtain across vision needs immediate assessment. Do not wait to complete a worksheet.

## Sources for this information

These references support the information on this page. Follow the linked source for its full context.

- [NHS — Floaters and flashes in the eyes](https://www.nhs.uk/symptoms/floaters-and-flashes-in-the-eyes/)
- [National Eye Institute - Floaters](https://www.nei.nih.gov/eye-health-information/eye-conditions-and-diseases/floaters)