Sahih Muslim Book 4, Hadith 129
People should avoid lifting their eyes towards the sky while supplicating in prayer, otherwise their eyes would be snatched away.
The Messenger of Allah (ﷺ) said: The people who lift their eyes towards the sky in Prayer should avoid it or they would lose their eyesight.
The Messenger of Allah (ﷺ) came to us and said: "How is it that I see you lifting your hands like the tails of headstrong horses? Be calm in prayer." He (the narrator) said: He then again came to us and saw us (sitting) in circles. He said: "How is it that I see you in separate groups?" He (the narrator) said: He again came to us and said: "Why don't you draw yourselves up in rows as angels do in the presence of their Lord?" We said: Messenger of Allah, how do the angels draw themselves up in rows in the presence of their Lord? He (the Holy Prophet) said: "They make the first rows complete and keep close together in the row."