What Is Phosphene And Why Does It Happen?

Phosphenes are visual phenomena that give the impression of seeing light without an actual light source. They may appear as light spots, wavy lines, swirls, or flashes of bright colors. That’s why many refer to this experience as “seeing the stars.” What Is Phosphene and Why Does It Happen?

People are often exposed to phosphenes as a result of eye trauma, compression, inflammation of the optic nerve, or rubbing against the retina. Although the phosphenes themselves are not considered dangerous, their persistence may indicate a more serious problem that requires medical attention.

What are Phosphenes?

Phosphenes are colored flashes of light produced from inside the eye rather than from an external light source. Some people say that phosphenes look like rapidly moving stars or shapes of color that slowly wander through your field of view. The passing of phosphenes is called photopsia. It can come on very quickly and resolve after a few minutes, or you may have a recurring feature in your vision. One or both eyes may be affected by this condition.

A common practice that often triggers phosphenes is eye rubbing. This action stimulates photoreceptors within the retina. It causes light and colors to emerge. Often times, phosphenes will continue to float visibly in the visual field a few minutes after the pressure on the eyes has been removed. While the reaction is a pretty cool phenomenon, rubbing your eyes can injure the eye as well as the skin and muscles around the eyes.

Why Do You See Phosphenes?

Seeing phosphenes occurs when a source (other than external light) stimulates the retina and/or optic nerve. The “source” that triggers retinal stimulation may include:

Increased eye pressure – It can be caused by eye rubbing, sneezing, blowing your nose, severe coughing, laughing or straining in any way, as well as a head or eye injury.

Low blood pressure – This is most common when someone stands up too quickly (it can also happen with dizziness).
Compression or inflammation of the optic nerve or retina – Incorrectly stimulating the retina and/or optic nerve can create phosphenes.

Age-related macular degeneration (AMD)

Age-related macular degeneration (AMD)

Phosphenes are often a symptom of an underlying condition such as:

Posterior vitreous detachment – A condition that occurs when the vitreous pulls away from the retina. It is caused by age-related thinning of collagen within the eyeball. This is a natural, non-threatening situation.

Diabetic retinopathy – This is retinal damage caused by uncontrolled blood sugar levels. If diabetic retinopathy is not treated, it can cause vision loss.

Age-related macular degeneration (AMD) – It is the deterioration of the middle part of the retina called the macula.
Retinal detachment – A condition where part of the retina separates from the back of the eye. Unlike vitreous detachment, retinal detachment is a serious medical emergency.

Optic neuritis – Inflammation of the optic nerve that can damage the protective sheath (myelin) that surrounds the nerve. It usually occurs in people with multiple sclerosis (MS).

Ocular migraine – Blind spots, floaters, flashes, or wavy and flickering

Ocular migraine – Blind spots, floaters, flashes, or wavy and flickering

Ocular migraine – Blind spots, floaters, flashes, or wavy and flickering colored lights in a person’s vision. Ocular migraines are caused by decreased blood flow, blood vessel abnormalities in the retina or at the back of the eye.

What Is Phosphene and Why Does It Happen?

Vertebrobasilar insufficiency – A medical condition characterized by poor blood flow to the back of the brain. In contrast, the part of the brain that controls vision and coordination is deprived of oxygen.

Charles Bonnet Syndrome (CBS) – A phenomenon that affects people who have partially or completely lost their sight, where they still “see” things that are not there. GIS results from the brain’s adaptation to losing visual stimulus.

What Is Phosphene And Why Does It Happen?

What Is Phosphene And Why Does It Happen?

Symptoms and signs

The most common sign of experiencing phosphene is seeing tiny specks, wavy lines, or stars moving in your field of vision. While such eye floaters may feel like something is on or very close to your eye, the source is actually inside the eye.

Other common symptoms of seeing photopsia or phosphene include:

  • Floating shapes or dots in the eyes that move with it.
  • Twinkling lights.
  • Snow, static or fuzz in the field of vision.
  • Flickering or flashing zigzag lights.
  • Bright, vibrant colors.


Seeing phosphene is not actually a condition itself, but a symptom of an underlying problem (or an external factor such as eye rubbing pressure). Treatment will be determined by the pre-existing condition.

What Is Phosphene And Why Does It Happen?

What Is Phosphene And Why Does It Happen?

The persistent appearance of phosphenes may indicate a change or worsening of a pre-existing condition or the development of a new condition and should be evaluated by an eye care professional. Phosphenes can be irreversible if damage to the brain, optic nerve, or other parts of the eye is severe enough.

When to See a Doctor? What Is Phosphene and Why Does It Happen?

As noted above, experiencing an occasional phosphene after a strenuous task is normal and not cause for concern. However, if phosphenes persist and are accompanied by any of the following symptoms, you should seek medical attention:

  • Weakness.
  • dizziness.
  • Headache.
  • double vision.
  • Nausea or vomiting.
  • low blood pressure.
  • Numbness.
  • Temporary loss of consciousness.

Regular eye exams allow your eye doctor to identify any underlying problems that may be causing your phosphenes and prescribe the appropriate treatment.

You may also like...

Leave a Reply

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