edit: Thank you to all who answered! I’m amazed at how many ways you came up with to answer this.

  • NeoNachtwaechter@lemmy.world
    52·
    3 months ago

    Because the mirror flips your eyes!

    You got a left and a right eye. Now if you had a top and a bottom eye instead, then the mirror would not flip left and right, but top and bottom.

    Buuut… if you had 4 eyes: left, right, top and bottom, then the mirror would flip them all!