As you progress through the Bog of the Forgotten, you will eventually come to a circular room with a large push panel on the floor, and two gated alcoves either side of it. The exit is blocked by large gate as well. This gate can be fully lowered when both push panels are pressed, however the gate only remains lowered for a limited time once either of the push panels are stepped off of.
To get to the Gorgon Eye hidden in this room, first use Typhon's Bane to destroy the vines covering the grapple point, and then use the grapple point to sling up to the unmarked chest containing the treasure.
Now to solve this puzzle. First, pull the lever that is to the right of the closed gate. Doing so lowers both of the gates on either side of the room. The alcove on the right side of the room contains a body. Leave the body alone for now, and instead make your way to the alcove on the left side of the room. This alcove contains a switch. Attack the wall to create an opening, revealing a water stream. Step into the alcove on the other side of the room, the one that contains the body, and destroy the wall there, too. A couple of Fiends will appear. Simply kill them with multiple grabs. Pick up the body and place it in the water. Run across to the other alcove and wait for the body to appear in the water stream on that side.
When the body appears, pluck it out of the water and place it on the switch. Now, stand on the switch in the middle of the room. Both of the gates blocking your progression are now open, and with this setup, you have enough time to make it through both gates before they close. Run off of the button and move past the now lowered gate.This video is from our unofficial game guide. You can view the full guide here