I searched the web but i can’t find a proper answer. Also, they could happen with and without headache.
Can somebody explain why they happen? What cause them?
The exact cause of scintillating scotoma is not fully understood, but scientists have some ideas. It’s believed to be related to changes in the blood flow and electrical activity in the brain. When a migraine is about to happen, there may be a sudden narrowing and then widening of blood vessels in the brain, which can affect the way our brain cells function.
These changes can trigger a chain reaction, causing abnormal electrical signals to spread across the visual cortex, the part of the brain responsible for processing what we see. These abnormal signals can disrupt normal vision and create the shimmering or flickering patterns that you experience during a scintillating scotoma.
In my case a combination of tiredness, low blood sugar and bright light seems to be the cause.