Nanoparticles are the most common nanocarriers for ocular therapeutics due to their biocompatibility and their capacity to be loaded with drugs and gene therapies by chemical attachment, embedment, or encapsulation in the nanocarrier. Highlighting four types of nanotechnology-based ocular drug delivery systems delivering their payloads to the back of the eye show, clockwise starting at noon: nanopolymer, nanoemulsion, nanomicelle, and liposome.