Hi there, it is most certainly ringworm. If it hasn't gone away yet, I would suggest pasturing him out in the sun. A lot of times the sun will clear it up. It's one of those things that is really hard to get rid of, you basically have to let it run it's course. It will probably spread, but it will eventually go away. I have an 8 month old heifer with it right now. She started off with a small one by her eye like your calf, but now it's spread to most of her head. It's nothing to panic about, just be sure to wash your hands after you touch him. And if you have other animals, especially cows, you should separate them and make sure you clean his stall before you put another animal in there.