How to Get to Dark World early with mirror glitch in Zelda

By using the mirror glitch, it's possible for Link to enter the Dark World earlier than the game intended. Take a look at this instructional video and learn where and how to perform the mirror glitch to travel to the Dark World early on in Zelda: A Link to the Past. Note that this glitch works on the Game Boy Advanced and the SNES emulator, but doesn't work on the Super Nintendo console.