He knows the food is there but he misses often when he snaps for it. I was able to use the skewer at first to get the food literally right on his mouth so he wouldn't miss it... But now he knows that the food must be near if he can sense that skewer in the water. I don't have to move the food as much now... I just use the skewer to get him to go in the right direction. Once he gets close enough that his head taps in, he can usually get it by himself. Yesterday I noticed that he kind of sucked it into his mouth when it wasn't right there instead of trying to snap at it.
I only noticed that he was blind on Thursday... It was the same day I first started using the skewer. I got him to eat three pellets after not eating for like two weeks. I realized that he actually was still hungry, but he just couldn't find the food. I mistook his attempts to snap at the food for him just taking a breath. It wasn't that long ago that he was still following my finger... So he must of had trouble seeing the small pellets but could still make out my (much larger) finger. It seems to have developed slowly over the month that I've had him.