When throwing an "Eye of Ender" in the game and then exiting the world (leaving the game), the Eye of Ender disappears upon returning, even if multiple Eyes of Ender were thrown. The issue results in the loss of all Eyes of Ender that were previously thrown, and players need to throw new Eyes of Ender again.

Steps to Reproduce:

1. In the game, throw an "Eye of Ender".
2. Exit the world or leave the game.
3. Return to the same world after exiting.

Expected Result:
After returning to the world, the previously thrown Eyes of Ender should still be visible and retrievable, allowing players to continue their exploration.

Observed Result:
Upon returning to the world, all previously thrown Eyes of Ender have disappeared, requiring players to throw new Eyes of Ender for navigation purposes.

Note: The issue may also apply to multiple thrown Eyes of Ender, where all of them vanish upon re-entering the world.