Have had ocular migraines now and again but recently had what you have referred to. Thought I was getting a migraine so closed my eyes and took deep breaths for several minutes. When I thought it passed I started to read some mail and found it was difficult and some words I couldn’t read at all even though I knew what the word meant. For example the word Nissan. I couldn’t begin to read the word but my mind new I had one in the garage. Then I realized I couldn’t remember the names of my dogs, friends and places. I was pretty panicked but the whole situation probably lasted 30 minutes at most. Scary stuff.