Can migraines cause permanent fuzzy/flashy vision?

Fuzzy flashy vision. Hello. When was the last time you had your vision checked? I wouldn't pin these "permanent" symptoms on migraines as there may be other explanations for these visual disturbances. See ophthalmologist first about these symptoms. If they clear you, they may recommend being seen by neurology since normally these symptoms leave when the mgraine leaves.
No. However, something can be wrong that could cause both the vision problem and headaches. See your GP and perhaps an eye doctor. It would not be 'caused' by the migraine - if the headache is actually that sort or not. Best wishes!