English: Rabbi Elazar said: Whoever gazes at the image of a wicked person — his eyes grow dim, as it is said “When Yitzchak was old and his eyes were too dim to see,” because he gazed at Esav the wicked.
On the daf / in context: The dimming of Yitzchak’s sight is attributed (in part) to looking upon Esav; the Gemara also records that it is improper to gaze at the face of a wicked person.
Type of Learning
Custom (Bavli — gazing at a wicked person dims the eyes)
What Is Learned
Gazing at the face of a wicked person can dim one’s eyes; Yitzchak’s loss of sight is linked to his having looked upon Esav.