Seeing a flash of light in your vision is often associated with conditions that affect the back of the eye called the retina. A flash of light may be a symptom of a serious eye condition and should always be reason to seek eye care quickly.
Defining What a Flash of Light Is
To understand what the “flash of light” symptom of conditions like retinal detachments or posterior vitreous detachments, it is important to understand the distinction of normal vision changes compared to abnormal ones.
If there is a sudden change in the lighting, for instance going from a dark movie theater to a bright sunny day, you may experience bright lights or dark spots in your vision. These are not considered symptomatic flashes of light.
Similarly, if a bright light is shone into the eyes, there may be an afterimage that persists for a few seconds, and it is also not considered a flash of light.
What is considered a flash of light, then? Typically, these flashes of light are described as if there was a lightning bolt that came across the vision for a moment.
Other descriptions include seeing a flash as if a camera had just taken a picture.
Possible Causes of Flashes in Vision
While there are many potential causes of flashes of light in your vision, the most concerning cause is a retinal detachment.
Other possible causes of flashes are a posterior vitreous detachment, migraine headache with a visual aura, or conditions like retinitis pigmentosa.
How a Retinal Detachment Causes Flashes
A retinal detachment can occur from traction that results from the gel like part of the eye called the vitreous pulling on the retina in the back of the eye.
This traction can cause the retina to break and pull away from the back of the eye – resulting in a retinal detachment.
When the retina is being pulled due to traction, the cells which are responsible for creating vision are stretched and stimulated by the tension.
Flashes from Posterior Vitreous Detachment
Like a retinal detachment, a posterior vitreous detachment occurs when the gel like substance pulls away from the retina. However, in a posterior vitreous detachment, the retina remains intact and the vitreous separates without causing a break.
Again, the tension caused by the vitreous results in the perception of a flash of light in the vision.
Flashes from Migraines with Aura
The flashes of light associated with migraines may mimic those seen with retinal detachments or posterior vitreous detachments, but there is no physical cause for the flash of light.
In these migraines, all of the perception is caused by neurological changes rather than actual changes in the eyes.
An eye examination would likely find no abnormalities or irregularities associated with these flashes of lights.
When to See an Eye Doctor for Flashes of Light
Any time you notice a flash of light in your vision, you should consult with your primary eye doctor. The best option is to first call and discuss your symptoms and situation and determine whether an examination is needed.
If an eye examination is needed, dilation will be used to better view the entire retina and check for a retinal detachment or posterior vitreous detachment.
