No doubt there's a few: the strength of the original story, the point at which said kanji resides along the path to long-term retention, the slight changes wrought by novel fonts or unexpected forms in the odd character, and so on.

But the biggest hurdle, for this reader, is rapidly advancing presbyopia. I've been so spoilt by all those big characters on the backlit screen, over there in the Review section.

Off to the chemist to buy stronger readers .... reckon being able to SEE 'em will help.

The same thing seems to be happening to me. I don't think its my eyes though. I can study a word to maturity in Anki with the nice big, black, block font but whenever I see the word in a book, I will just draw a blank! When I go to look it up, I realize, "Hey! I know this word!" Its really frustrating because it feels like all that studying went to waste. I think the only real solution is to keep on reading! Maybe it will stick in my mind if I see it enough

The tiny kanji in most books are frustrating. With even tinier furigana! The different fonts are tough as well.

I bought a new iPad 3 and have several Japanese dictionaries and apps plus some books in Japanese. I can make the fonts huge and they are very clear.

I also bought one of these for paper books:

http://www.amazon.com/UltraOptix-LED-Lig...ying+glass