
I think I watch a video once. It has nothing to do with the eyes. In the mythology it was said that Seth try to sexually dominate Horus but failed. Horus caught Seth semen and come up with a plan with his mother by puting Horus cum into Seth favorite food which is lettuce. The trials come and when they check if Seth claim about dominating Horus was true or not. They couldn't find the Seth cum in Horus body but they found Horus cum in Seth body which they take it as Horus impregnating Seth. There are also multiple versions of Seth being "pregnant" but he didn't give birth to human child but creatures like monster. The pregnant part is more symbolic than Seth actually getting pregnant in a literal sense.
wait ! isn't there an myth where Seth gets pregnant by horus and it has smthin to do with horus's eye?