Disappearing Eyes

Question
Hello....I have a community freshwater 30 gallon tank. I have just discovered that two of my neons and one platty have lost one eye. There is no evidence of injury...they eyes are just gone. Is this a disease? The most recent entry to the tank is a ghost knife. Could he be the culprit?

Answer
That is the strangest thing I ever heard (read my answered questions and you will see some far out ones). The new fish could be a culprit. Try moving him into a seperate tank and watch the other fish to see what happens.

Please forgive the lateness of my reply.