I heard about a nice exercise to recover from strokes, using visualization. I cannot explain in detail how it works, but the idea is that you start with a white ping pong ball, and try to recreate it in your 'inner screen/mind' exactly as it is, in your mind. and then maintain it for up to 15 min, if you can reach it eventually. Then stage two, use something more complicated such as an apple or an orange, and recreate it perfectly as it is, as you keep it in front of your eyes for a while. Then the fun begins, stage three, recreate the room that you are in, after you look around it for a minute, intently. Advanced stages involves recreating a whole building, or street, and then even whole towns. But this will take decades for most of the people. Reaching the phase where you can recreate a whole city in your mind and maintain it, this may or may not help you to have an almost photographic memory.
If you like the idea, test it. I just reached the room, and I can make it let's say 70-80%. If you have a bookshelf with books in that rook, may the gods of luck be with you.
I have heard about this or similar techniques. The problem I might have with it is that I have to build my minds eye picture from scratch as it is. It is incredibly energy consuming a d wears me out. It is like doing a math problem in the head all day...