Chitosan (CS) is a hemi-synthetic cationic linear polysaccharide produced by the
deacetylation of chitin. CS is non-toxic, highly biocompatible, and biodegradable, and it has a
low immunogenicity. Additionally, CS has inherent antibacterial properties and a mucoadhesive
character and can disrupt epithelial tight junctions, thus acting as a permeability enhancer. As such,
CS and its derivatives are well-suited for the challenging field of ocular drug delivery. In the present
review article, we will discuss the properties of CS that contribute to its successful application in
ocular delivery before reviewing the latest advances in the use of CS for the development of novel
ophthalmic delivery systems. Colloidal nanocarriers (nanoparticles, micelles, liposomes) will be
presented, followed by CS gels and lenses and ocular inserts. Finally, instances of CS coatings,
aiming at conferring mucoadhesiveness to other matrixes, will be presented.