Have I had a migraine?

A couple of weeks ago I was siting in my work van and I lost vision at my point of focus in both eyes, like blind spots. Letters on my phone disappeared and I found it hard to read.I started feeling generally unwell and as if I was going to faint.The blind spots disappeared but I could see a rippling effect to the left of my vision which went away after about 5 minutes. The whole episode lasted about 20 minutes.I went to A&E and they did bloods, ECG and CT scan of my head. All results normal. This happened again 2 days ago and it's really worrying me, same visuals again and has left me feeling wiped out. I panicked and rang 999, and had all the same tests again and again all normal. Nobody has mentioned migraine to me and I've never had them before (I'm 54 yo male). Thing is I don't get any headaches or pain while it's happening just massive panic and anxiety.Thanks in advance.