What happens when you rub your eyes and see colors?

Most of us have experienced it. You rub your closed eyes, or sneeze, and suddenly you notice some flickers or sparks of light in your vision.

But, by the time you open your eyes, they’re gone. These small lights are usually phosphenes, a visual phenomenon caused by mechanical stimuli resulting in pressure or tension on your eye when your eyelids are closed.

How the retina works

The internal lining of your eyeball is called your retina. The retina’s job is to take visual information entering your eye through the pupil and convert this information into an electrical signal.

The electrical signal is then sent to your brain to provide you with the visual image you see of the world. Phosphenes are generated by the retina after there’s some sort of stimulation, even with your eye closed.

What stimulates the retina

• Sneezing
• Standing up too quickly
• Head trauma
• Looking at the sky
• Moving your eyes quickly

Phosphenes

Usually, phosphenes are described as sparks, twinkling lights or pin-prick light shapes that can be brightly colored. Phosphenes will subside quickly — in less than a few seconds — and don’t cause any change to vision.

Other reasons for seeing colors

Migraines and auras

Visual patterns or sudden lights in your vision also can be caused by ocular migraines, or auras. Auras generally last from 20 to 60 minutes and start slowly in one area of the vision. They grow over a course of minutes to cause a scotoma, or blind spot, with your eyes open or closed. Usually, auras precede a headache or migraine and have geometric-associated shapes and shimmering colors. After auras subside, vision will return to normal.

Retinal tears or detachment and photopsia

Flashes of light, or photopsia, which occur with the eyes open or closed due to a retinal tear or detachment are due to mechanical tugging of the retina. This tugging can cause a tear in the retina, pulling away from the eyeball and causing a detachment. These flashes are seen intermittently after development of a retina tear or detachment and usually don’t subside until it’s repaired. The retina doesn’t sense any pain or discomfort; flashing lights can be one of the first signs that there’s a change in the retina. Retinal tears and detachments are sight-threatening and need to be evaluated immediately by an eye doctor.

If you’re concerned about any lights you see in your vision or have new flashes of light, it’s best to have a dilated eye exam. Even if you have no change in vision or don’t wear glasses or contact lenses, an annual dilated eye exam is encouraged to evaluate the health of your retina before any problems develop.