Neuro-ophthalmologyNeuro-ophthalmology is the branch of ophthalmology dedicated to the study of neurological conditions which affect the visual system. An adequate understanding of the aetiology and pathophysiology of neuro-ophthalmic conditions is fundamental for establishing successful therapeutic strategies. Animal models are therefore considered crucial for understanding and investigating pathological events. Several animal models have been developed for studying neuro-ophthalmic disordersNeuro-ophthalmic disorders. However, their validity is closely related to the level of similarity with human pathology. Rodent models are extensively used due to their accessibility and cost efficiency. In particular, mouse models are recognised as among the best genetic models due to the ability to alter their genomes easily. Rats are easy to breed and are mainly used for toxic/pharmacological and surgical models. Nevertheless, rodent models are still suboptimal for human neuro-ophthalmic conditions because of anatomical differences between species. Primate models have the advantage of sharing vast anatomical and genomic similarities with humans. However, monkeys are expensive, difficult to breed and can only be handled by qualified personnel, limiting their suitability. Hence, there is no perfect species for studying neuro-ophthalmic conditions. This chapter will focus onOptic Neuritis (ON) the most common animal models of neuro-ophthalmic conditions.