From what I can see his eyes look fine. If they ever appear to be sunken in to you one of the first things you can try is a nice long
bath/soak and to offer a few drops of water onto his snout. This is often a sign of dehydration. Make sure you offer him water 2-3x a day.
What are his temps in his enclosure? It looks to me that he is simply regulating his heat in these pics by opening his mouth. This is actually a good thing as long as it's not happening constantly. It shows he's reaching temps high enough for his likings. Also what type of
UVB light are you using? Just so we can make sure this isn't bothering his eyes.