Some puzzles (Skull Woods' Boss Key, Lorule Castle's Hookshot Trial) require you to place eyeballs into pedestals. Once an eyeball is thrown into a pedestal, it is activated and the eye is stuck in it.
When an eyeball is picked up, the last position it had on the ground is stored as an invisible object with no collision, and is normally impossible to interact with. However, when throwing the eyeball into the pedestal, it is possible to interact with the invisible object during the animation where it falls into the socket of the eye, which results in picking the eyeball back up again.
With correct timing, you can lift the ball right as it activates the pedestal, and then use the same ball to activate the second one, effectively duping the eyeball.
Stand far away north or south of a pedestal and throw the eyeball towards it so that it's close enough that it can be picked up and thrown into the pedestal without moving.
Walk up to the eyeball and throw it again, this time into the pedestal
Press A to pick up the eye again when the pedestal emits a circle of light (roughly a half second window).
For speed, you will want to throw the eye so that it bounces off the pedestal and back towards you, as this will put the ball within range of the pedestal, and be closer to Link.
It is better to pick up the eyeball too early rather than too late as you can just throw the ball again indefinitely.
Once you've activated the first eye pedestal, you will NOT be able to pick up the eyeball again if it is dropped because the game will store the first pedestal as the last place where the ball has been picked up, so beware of Keese and Wallmasters while doing this. You can still Hookshot it however.