I found it in the Knyttlevels archive and gave it a try out of curiosity. I might be mistaken, but there doesn't seem to be any other way to reach that power-up except executing a really precise double jump (in fact, the entire level seems to be based on pixel-perfect jump challenges, which aren't exactly my cup of tea). On top of that, you have to land on a very specific spot in the water pit below, and that spot is not visible until you get the eye. This means you're practically guaranteed to fail the first time you manage to reach the power-up, so you'll have to repeat the process quite a few times.
I suppose you could use the cheat code or the level editor to skip that part, if you want to check out the rest of the level.