What was the purpose of placing the coins over the eyes of the dead in Greek mythology?Im aware that placing the coin in the mouth was to pay your...

In Greek mythology, the recently deceased would be sent
down to Hades, or the underworld.  In order to pass over the rivers Acheron and Styx,
you would have to pay the toll- a coin, left in the mouth of your dead body.  Most
primary sources about Hades mention specifically putting the coin in or near the mouth,
although it seems that putting two gold coins (one over each eye) was also a method used
occasionally.  If the dead were not buried with a coin in the mouth or on the eyes, he
or she would be doomed to wander around in the entrance to Hades, before the rivers
which served as a boundary.  Essentially, he or she would be in what the Christians call
"limbo".