While he didn't have anything to do, Leon focused on scanning his eyes over and over again, and compare them to the known eyes in the books that he collected. He noticed that, his eyes were very different from all the eyes that was in the books. But that didn't mean that he was clueless about how to improve them, basically all eyes have the same function, so his eyes weren't that out of the norm. But he didn't want to blind himself, so he planned to gather as much data as possible before he started to cultivate an eye technique. Even without taking the rest of the techniques that Theo was collecting, he could create an eye technique, but he didn't want to just see the things that he couldn't at the moment. Leon also wanted to create illusions with them, he thought it would be a waste if he didn't fully unleash potential of his eyes.