Why does Magic Leap need another $827M?

Augmented reality startup Magic Leap is reportedly raising $827 million in a third round of funding, according to Forbes.

If it succeeds, it will be a strong signal of investor confidence in the fledgling technology, which can overlay animated imagery on the real world using glasses with special displays. Augmented reality is expected to become a $120 billion market by 2020, according to tech adviser Digi-Capital.