I haven't had double vision but I have had different visual warnings... it is a "prodrome."

Visual changes such as flashing or flicks of light, or halos are called auras, but other "premonitions" are called prodromes.

It could be emotional changes, burst of energy, visual issues beyond "light" connected and the like. They are often difficult to nail down because some can occur a day or two ahead of a migraine!

I have many different types, and often forget that I need to take my medicine right THEN.

((((feel better))))