**6. Conclusions and Perspectives**

It is established that eye damage is a leading cause of irreversible vision loss resulting from ocular diseases. The current standard treatments helped in both preventing and curing several pathological conditions, especially when related to the deep sections of the eye. However, many of these methods are rather invasive in terms of procedures, with a consequent possibility of promoting infection, inflammation, or even retinal detachment with potential risk of vision loss. These limitations impose considerable costs on patient quality of life and have an enormous economic impact on the health care system. The progress in the nano-engineering field can help boosting the discovery of a new approach for ocular diagnosis and therapy. Noble metals NPs and bio-inspired NPs represent a powerful tool to overcome all the limitations coming with standard treatments due to their physico-chemical properties. NPs can in fact penetrate deeper inside the ocular segments and also locally deliver high dosages of drugs, enriching local drug concentration when applied topically. In addition, the plasmonic properties of Au and Ag can have an added value to contrast eye diseases. However, numerous challenges still remain to be addressed as there are still limited numbers of in vivo studies. In addition, a deeper toxicology assessment is required for the development of new systems for ocular treatments.

**Author Contributions:** Conceptualization, V.D.M.; writing—original draft preparation, V.D.M.; review and editing, L.R. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding.

**Acknowledgments:** VDM kindly acknowledges Programma Operativo Nazionale (PON) Ricerca e Innovazione 2014-2020 Asse I "Capitale Umano", Azione I.2, Avviso "A.I.M: Attraction and International Mobility" CUP F88D18000070001.

**Conflicts of Interest:** The authors declare no conflict of interest.
