It is narrated from Sayyiduna Jabir bin Samurah (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "People must desist from raising their gaze towards the sky in prayer, lest their sight never be returned to them."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 3538