More than meets the eye: Cortical & white matter mapping to understand visual system pathologies: Information transmission within the visual system is highly organized with the ultimate goal of accomplishing higher-order, complex visuo-spatial and object identity processing. Perception is dependent on the intactness of the entire system and damage at each stage-in the eye itself, the visual pathways, or within cortical processing-might result in perception disturbance. In my talk, I will review several examples of lesions along the visual system, from the retina, via the optic nerve and chiasm and through the occipital cortex. I will address their clinical manifestation and their cortical substrate. The latter will be studied via functional magnetic resonance imaging (fMRI) and Diffusion Tensor Imaging (DTI), enabling cortical, and white matter mapping of the human brain. Special attention will be given to the temporal aspects of visual perception following optic neuritis, a demyelinative disease of the optic nerve. To that end, we demonstrated a persistent motion perception deficit in these patients (Raz et al. Neurology, 2011) and suggested that demyelination was probably the cause for these temporal deficits of perception (Raz et al. Annals of Neurology, 2012). Furthermore, studying the fellow clinically unaffected eye of optic neuritis patients, we argue that visual projection via this eye reflects an adaptive process. This adaptation contributes to temporal synchronization of binocular visual information and improves binocular visual functions (Raz et al. Neurology, 2013, Benoliel T., MS journal, 2017). Through the optic neuritis model as well as other visual system pathologies, I hope to highlight the importance of studying disease states to better understand the mechanism of visual perception.