3 Causes of Flashes of Light

Persistent Flashes After Posterior Vitreous Detachment (PVD)
December 15, 2010
FDA Denies Iluvien
January 10, 2011
Show all

3 Causes of Flashes of Light

The cause of flashes of light are often due to a posterior vitreous detachment, but there other possibilities, too.

Causes of Ocular Flashes

There are several causes of flashes.  The most common cause is a posterior vitreous detachment (PVD), but a retinal tear, migraine and inflammation can also cause the same visual symptoms.

In other articles, a PVD  and retinal tear have been well covered.

Flashes Due to Migraine

Without getting too specific, there are visual migraines that yield a scintillating light pattern, often confused with flashes.  The array of lights lasts about 20 minutes and migrates across the field of vision.  For instance, it may move from “right to left” over the 20 minute period.

This pattern generally resolves, or, there may be headache or other ocular symptoms that develop.  These, too, last only for a finite period.

Any migraine, or symptoms that you feel are migraine related, should be evaluated by a doctor as there are other neurologic conditions that can give the same symptoms.  This diagnosis, while seemingly benign, should be made as a diagnosis of exclusion, that is, make sure all other possibilities, such as tumor, are ruled out.

I often refer these types of cases to a neurologist or neuro-ophthalmologist to make sure I’m not missing something.

Flashes Related to Inflammation

Inflammation inside the eye is called uveitis, or iritis.  It is very similar in nature to arthritis, another type of inflammation.  Like arthritis of a joint, inflammation can occur just inside the eye.

Most commonly the inflammation is in the front of the eye, but on occasion, there can be types of inflammation affecting the retina.  Symptoms can include flashes of light.

The best way to diagnosis retinal or retinal vascular inflammation is with a dilated eye exam.  It is also probably prudent to seek the opinion of a retinal specialist in this case.

What Does This Mean?

In medicine, “everything has a differential.”  In other words, in medicine, for a given symptom, it is a doctor’s responsibility to think of all the causes of a particular symptom.

For instance, flashes of light are often caused by a PVD or retinal tear, but could be caused by migraine or inflammation.

Enhanced by Zemanta


  1. Mehdi says:

    Dr. Wong, I am a young man from morocco. I was hit on the eye playing basketball and started seeing flashers since. The eye in question was injured 20 years ago which makes it very difficult to dilate so my doctor cannot see the peripheral retina. Is there any way to check out the peripheral retina without pupil dilation? How about the optomap? Thank you very much in advance for your consideration.

    • Dear Mehdi,

      I think I may responded via email, but for the rest of the crew,

      an ultrasound of the retina, call a B-scan, is the next best thing to a dilated exam.

      Optomap are okay for screening and probably could detect an large/obvious retinal detachment.


  2. Martha Garcia says:

    I hit my left eye very hard on a the car trunk, and a day later started seeing flashes of light and today I’m seeing floaters, should I see an eye or medical doctor?

  3. Darren says:

    Dear Dr Wong,

    Are there specific flashes that are associated with a certain condition. For eg. i used to see sparkles in the side of my vision when my retina tore. Recently, i began to see something like a photography flash, and instead of it happening at the sides, it seems to affect the whole field of vision. Can this be a retina detachment?


Leave a Reply

Your email address will not be published. Required fields are marked *