What could cause blurred vision after a flu?

Hello doctor,

About a month ago I had a bad flu. While I had this flu, my eyes were itchy and watery. I began rubbing one eye and I noticed a 'flash burn' in the vision. This is like when you look at a bright light and there is a flash burn for a minute or so. Well, this burn happened all of a sudden without me looking at anything bright. I waited for several minutes but the burn did not go away. It has now been about a month and that burn is still in my vision. It has not gotten worse but it has not gotten better. The burn mark blinds my vision in that area so I am depending on what I look at. I am not able to see just in that burn mark. My eye tries to compensate for it and sometimes it works but the problem is still there. I am wondering if it is a corneal scratch or something more serious.

Kindly suggest. Thank you.