Flashes occur when the vitreous gel bumps, rubs, or tugs against the retina. Like floaters, flashes are generally harmless and require no treatment.
But flashing lights can be caused by several different medical conditions, including retinal detachment, shrinking vitreous humor, eye hemorrhage, stroke, or migraine. Some flashes are best ignored. But if they’re new, intense, or very disturbing, they could be a sign of a serious illness your doctor should treat.
If you see flashes suddenly and in a greater amount than usual, you should definitely see your optometrist or doctor immediately. A sudden and unexplainable surge of these types of flashes can indicate the vitreous fluid inside your eye is pulling away from the retina, the light-sensitive layer at the back of the eye.
What about flashes of light? Small arc-like momentary flashes of light in the peripheral vision are commonly experienced during vitreous separation. The vitreous pulls on the retina which makes one think they are seeing a light but it is caused by the movement of the retina.
The easiest way to get rid of flashes and floaters in the eye, at least temporarily, is to move your eyes up and down (this is more effective than moving your eyes side to side). This movement shifts the fluid around in your eye and moves them out of your field of vision.
Flashes and floaters are one of those problems that can be quite serious and you should get to an eye doctor or eye care provider as soon as possible. The eye has fluid in the front of the eye called aqueous.
Dehydration, stress, lack of sleep, caffeine and certain foods are typical triggers for ocular migraines. When someone describes their flash stemming from only one eye and it is a quick flash usually only seen in the dark almost like a flash from a camera then I often attribute this to the vitreous gel.
Low blood pressure can cause people to see stars or specks of light, particularly if they change position quickly. An example would be standing quickly from a sitting position or rising quickly after stooping or bending over. Pregnancy related high blood pressure (pre-eclampsia) can also cause light flashes.
Some brain tumors can cause visual or auditory disturbances. 2 Problems with vision can include seeing flashing lights, double vision, blurring, and loss of vision.
This is called a migraine aura. Eye flashes from a migraine aura may appear like jagged lines or cause a person’s vision to appear wavy. As stress can be a trigger for some migraine attacks, it’s possible there’s a connection between stress, migraine, and eye flashes.
Light flashes. Sudden appearance of many floaters. A shadow or curtain over part of your visual field (usually this comes as detachment progresses; thank goodness mine didn’t go that far)
Symptoms The sudden appearance of many floaters — tiny specks that seem to drift through your field of vision. Flashes of light in one or both eyes ( photopsia ) Blurred vision. Gradually reduced side (peripheral) vision. A curtain-like shadow over your visual field.
During an ocular migraine, or migraine with aura, you may see flashing or shimmering lights, zigzagging lines, or stars. Some people describe psychedelic images. It may also cause blind spots in your field of vision.