It is narrated from Sayyiduna Ibn Abbas (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) forbade us from constantly looking at people afflicted with leprosy.
Hadith Referenceمسند احمد / ومن مسند بني هاشم / 2721
Hadith Gradingحکم دارالسلام:إسناده ضعيف، لمحمد بن عمرو بن عثمان وفي هذا الحديث اضطراب