For the first few centuries of microscopy, spatial resolution was limited by the diffraction barrier. Recently, this barrier has been broken using several different methods. Optical methods that provide better resolution than the diffraction barrier are referred to as super-resolution. Although these techniques have significantly improved resolution in two dimensions (x and y) or in the axial dimension (z), it has not been possible to achieve substantial improvement in all three dimensions simultaneously. A study by Bo Huang, Wenqin Wang, Mark Bates, and Xiaowei Zhuang demonstrated a breakthrough by achieving a spatial resolution that is 10 times better than the diffraction limit in all three dimensions without using sample or optical-beam scanning.