Ok it's there now. No, that is not sunken eye's. Veiled especially tend to retract their eyes a little when approached by a camera.
Some chameleons are shy about drinking. You have to observe the white portion of their poop to evaluate their hydration.
I got worried to when I saw my chameleon pull his eyes in a bit, then back to normal minutes later. Trust me though if his eyes are sunken you will definitely know. its unmistakable to miss. and I have the same issue. I have never seen my chameleon drink once! he must be a shy drinker, but urates are white so he definitely does. But darn I wanna witness him drink just once to see in person how its done. and where his drinking leaves are so I can spray that spot more often