Do you suffer from headaches or migraines? I have visual interference sometimes during migraines with or without a headache. I think they are migraines because my head feels odd but with no pain and other times I have pain, but I will get swirls of patterns in my visual field as if I was looking at light for a while. Or sometimes I will see flashes of light in my peripheral, or floaters and stars. I never really thought of them as hallucinations just symptoms of migraines, low blood sugar, low oxygen to the brain (low blood pressure), or high blood pressure.