Raising the eyes to the sky during salaat or looking to the right and left without due cause. As far as raising the eyes, it is forbidden and bears the threat of punishment. It is narrated by Jabir Ibn Samurah (radiallahu ‘anhu) who said: The Messenger of allah (sallallahu ‘alaihi wa sallam) said: Let the people stop raising their eyes to the sky in the salaah or let their sight not return to them. [Muslim] As far as looking around unnecessarily, it is a deficiency in the salaah of the worshipper as long as he has not turned his entire body in another direction [i.e. away from the Qiblah]. If however the entire body is turned then the salaah is invalidated. It is narrated by ‘Aisha (radiallahu ‘anhaa) who said: I asked the Messenger of Allah (sallallahu ‘alaihi wa sallam) about looking around in the salaah. He said: It is misappropriation pilfered by Shaitaan from the salaah of the worshipper. [Al-Bukhaari]. At-Tirmidhi also collected an authentic hadeeth: Be warned of turning or looking around in the salaah because it is destruction. And there are other ahadeeth on looking around in the salaah.