In all sincerity, black square glasses work well with
any face shape. That said, if you like to follow “traditional” fashion advice, here are some suggestions.
Square frames can make an excellent contrast for those with round faces. The angularity of the frames offsets round features in a striking fashion. If you have a
heart-shaped face, black square frames can bring more angles to it, creating a sharp look. For those with
triangle faces, square frames can underscore the unique shape by mirroring the angles in a reinforcing manner.
Just remember, how you feel about the glasses is what matters the most.