Thanks for the response Alex.
I understand what you mean about getting the images but not really understanding them. I think there is something about that in Luria's book. The thing is, there are aspects where you don't really need to understand the data as it is purely factual, where the eidetic thing would come in really useful - a set of dates for a history exam, for example, or, better still vocabulary in a foreign language! Wow, it would be So useful there.