[Kanji_The_Wanderer]

He had to tie Misa up like that and put the blind fold on. At this point, L doesn't know what the Death Note was. All he knew is that the 2nd Kira can kill just by seeing someones face. So they covered her eyes since they had no idea how Kira killed then.

Which goes to prove my point again that the manga is better then the anime.

In the manga, L is thinking before he dies, and it shows you what it is.

Also it is hard to say anything, or may even be impossible, when you are having a heart attack.