I am running a home campaign and one of my characters is in possession of a robe of eyes. Part of the item's ability is that the wearer can see into the Ethereal Plane as they want out to 120 feet.
For the "seeing into the Ethereal Plane" part, I take it that they are talking from the point of view that the character is currently in the Prime Material Plane looking into the Ethereal Plane.
If that same character were in the Ethereal Plane, does the robe of eyes allow them to see into the Prime Material Plane the same way they'd be able to see into the Ethereal Plane if they were on the Material Plane?