To find Mimir’s eye in Jotunheim in Reach in The Journey in God of War throw the axe and the orange panel until the platform has rotated all the way around:
Then throw the axe at the white disc below the orange panel to freeze the platform in place. Clear the rubble and climb up to the platform. When you are on the platform recall the axe and ride to the ledge. Pick up Mimir’s eye from the chest ahead.