Edward Poynter, Orpheus and Eurydice, 1862
It is often said that the myths from all over the world have commun subjects.
The taboo "looking back" is one of them.
"To look at someone (more precisely, to look squarely someone's eyes)" is traditionary a privileged right. Probably in Japan, it was much more special than Western countries.
You had to bow yourself on the ground when someone superior such as aristocrates, samurais passe in front of you. It was absolute taboo to look directly Emperor.
Even now it is very rude to look squarely someone superior (someone elder than you) so much.
The other way, to look someone gives you a special power. In Japanese, we have expressions such as "to kill (someone) by eyes". Having what a little knowledge of martial arts, I know very well that you should never read your mind by your adversary, but you have to kill (win) him by your eyes. In daily life, "the eyes say things more than the mouth".
During my fieldwork, I noticed that it still reminds in the Japanese custom. For exemple, when people move god's soul from the fixed shrine to the portable shrine, people put their head down. it is strongly forbidden to look at god directly. The eyes are window of the mind. You should never disturb people, by entering someone's mind "with your shoes (expression)". Maybe for this, Japanese know unconsciously hide their personal expression for social reason.
To look at someone must be much more special than now. The person who has this right must be considered having special power (political, magical, or both).
Certainly, we can easily find the taboo of looking back. Orpheus was forbidden to look back to his dead wife. In Japanese myth, we have almost same episode. The god named Izanagi, the creator of the Japanese peninsula and numerous gods, was forbidden to look at his dead wife, the goddess Izanami. He looked for his wife into the underworld to put her back to the world. It was strictly forbidden to look at her until they will get out from the underworld. However, he loved his wife so much, couldn't help to look her back. As Orpheus, he lost definitively his wife because he broke the taboo.
The taboo of eyes can rub everything from you. The eyes are such a important organ, and to look was much more precious sens than we think in our age.
Just one idea which I got while singing Pamina. No idea how to connect to academical discussion.