Experiencing flashes of light in your vision could be a symptom of various underlying issues, and it is important to note that this is a potential sign of a serious eye condition. Here are a few possible causes:
Migraine with Aura: Some people experience visual disturbances, including flashes of light, as part of a migraine episode. This is often accompanied by a headache and feeling nauseated. The flashes associated with migraines will usually last tens of minutes and the symptoms are referred to as a "visual aura".
Retinal Detachment: Flashes of light may be a symptom of a retinal tear or detachment. This is a serious condition that requires immediate medical attention to prevent vision loss.
Vitreous Detachment: The vitreous is the gel-like substance that fills the inside of the eye. As we age, the vitreous can pull away from the retina, causing flashes of light. The flashes from the vitreous gel pulling on the retina usually lasts seconds, is more noticeable in the dark and worsens with movement of the eye. While this is usually not harmful, it's important to have it evaluated by an eye care professional.
Ocular Migraines: Experiencing the visual When migraines occur without eye pain or headache, these are referred to as ocular migraines These are migraines that specifically affect vision and there is no accompanying headache. They can cause temporary visual disturbances, including flashes of light.
Other Eye Conditions: Conditions such as uveitis, inflammation of the eye, or other retinal issues may also cause flashes of light.
If you experience flashes of light in your vision, especially if they are sudden, persistent, or accompanied by other symptoms such as a sudden increase in floaters, it is crucial to seek immediate medical attention. An eye care professional, such as an optometrist or ophthalmologist, can perform a thorough eye examination to determine the cause of your symptoms and recommend appropriate treatment if necessary. Ignoring these symptoms could lead to serious vision problems.
The American Academy of Ophthalmology has an excellent Wiki on the "Ophthalmic Manifestations of Migraines" that includes the superb graphic representation of a visual aura and how it changes over time. For an even more in-depth review, there is also the September 2022 clinical update "What Ophthalmologists Need to Know About Migraine."