Unlikely to be food. Today I had eaten porridge for breakfast some 3hrs before, no other food.
@garygary Could be low blood sugar. In the past few years I’ve had several no-pain migraines, zigzags etc., sometimes gone blind in one eye, and always related to not having eaten for a few hours. I note you’d not eaten for 3 hours before your last attack. Can you remember how long it was in the previous two times? Also I find porage doesn’t ‘do’ it for me, I need protein and fat, graze all the time, seems to work for me. If I get stressed I need more food too. Flapjacks work well.