What is the prohibited degree of raising one's gaze during prayer, and is looking at a wall clock on the wall considered among the prohibited acts of looking towards the sky?

Raising one's gaze to the sky during prayer is disliked (makruh), and some scholars have even deemed it forbidden (haram) and rendering the prayer invalid, a view held by some Hanbalis. An exception to this is when one burps, in order to alleviate a noxious odor. This prohibition is understood by everyone and does not require further clarification.