It is narrated from Ibn Abi Hudhail (may Allah have mercy on him) that Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) went with one of his companions to visit a sick person. When they entered the house, that companion began to look here and there. Sayyiduna Abdullah (may Allah be pleased with him) said to him: By Allah! If both your eyes were gouged out, that would have been better for you.
It is narrated from Nafi' (may Allah have mercy on him) that some people from Iraq came to Sayyiduna Ibn Umar (may Allah be pleased with them both), and they saw a gold necklace on the neck of one of his maidservants (slave-girls), so they began to look at each other. Sayyiduna Ibn Umar (may Allah be pleased with them both) said: "You people’s eyes are very sharp when it comes to seeing evil."