I have a permanent after-image type spot in my left eye - it occurred with a bad headache around 8 months ago. (I've never looked into a migraine diagnosis) - I saw an ophthalmologist who examined my eye, determined there was nothing wrong with it, and that the spot was mostly likely 'migraine related' and would go away. It's still there, months later, and I'm concerned. It does not impair my vision, rather just looks like a permanent after-image, after looking at a bright light. Should I worry?