The physiological and anatomical barriers are major obstacles in the field of ocular drug delivery systems. The barriers involve nasolacrimal drainage, blinking, cornea, sclera, and blood-aqueous barriers whereas dynamic barriers involve conjunctival blood flow, lymphatic clearance and tear drainage. These barriers are showing natural protective functions, as well as limiting drug entry into the eye. Nanocarriers have been found to be effective at overcoming the problems and associated with conventional ophthalmic dosage forms. In this chapter emphasizes overcome to barriers and discusses advanced novel techniques used in the field of ocular drug delivery systems including nano dispersion systems, nanomicelles, lipidic nanocarriers, polymeric nanoparticles, liposomes, noisome, and dendrimer, have been investigated for improved permeation and effective targeted drug delivery to various ophthalmic site.