Flashes of light are pinpricks or spots of light that you see in your field of vision. People often say seeing flashes of light is like seeing "shooting stars" or "lightning streaks." Flashes of light in your vision come from inside your eye. They are not caused by lights or anything else outside of your body. 

Most flashes happen when the vitreous gel inside the eye shrinks or changes, pulling on the retina (the light sensitive lining of the eye). Flashes of light can also happen if you’re hit in the eye or rub your eyes too hard. In both cases, the flashes are caused by physical force on the retina.

Flashes of light usually appear and then fade quickly. In contrast, bright spots, lines or patches that appear and stay in place for a period of time may be migraine aura or a symptom of another condition. Migraine aura may look like shimmering jagged lines or appear wavy, like heat waves. Migraine aura can appear even if you do not get any headache.

Light rays or halos that you may see around lamps, headlights or streetlights may be a symptom of cataract or an effect from an intraocular lens (IOL) or refractive surgery.

Many people will see occasional flashes of light, especially as they age. These occasional flashes are usually harmless, but you should discuss them with your ophthalmologist during an eye exam. However, if you suddenly start seeing repeated flashes of light, this could be a serious problem, especially if you also have cloudy floaters  (gray or dark spots that move back and forth in your vision) or vision changes.

Call your doctor right away if:

• You suddenly start seeing flashes when you haven’t before.
• You have a sudden increase in flashes of light.
• You see flashes of light along with cloudiness or dark spots in your vision.
• You see a dark area or ‘curtain’ across your vision.
• You see flashes of light after being hit in the eye or face.

Suddenly seeing new floaters and flashes could mean your retina has torn or detached. This is a very serious condition that your ophthalmologist must treat quickly to prevent blindness.

There is no treatment for occasional flashes of light caused by vitreous changes from aging. Occasional flashes do not cause any damage and most people get used to them after a little while. If you’re seeing a lot of flashes of light, treatment of the underlying condition will usually reduce the number of flashes you see.

These conditions can cause flashes of light:

• Choroidal Neovascular Membranes
• Cytomegalovirus Retinitis
• Detached and Torn Retina
• Histoplasmosis
• HIV/AIDS
• Migraine
• Posterior Vitreous Detachment
• Stickler Syndrome
• Vitreomacular Traction
• Hereditary retinal diseases like retinitis pigmentosa or choroideremia

Other symptoms that may seem like flashes of light include:

• Distorted vision (with migraine)
• Halos around lights
• Starbursts around lights

For more information, see also: Floaters and flashes