What eye-movements tell us about Disorders of Consciousness?

In everyday life, eye movements (including fixation, smooth pursuit and saccades) are essential for interacting with the visual environment. In patients with Disorders of Consciousness (DoC), visual fixation and pursuit are considered among the earliest clinical signs of awareness recovery. However, the traditional distinction between reflexive and voluntary eye movements may be insufficient to interpret these behaviours, as movements that appear automatic can still recruit cortical networks. This review re-examines eye movements in DoC through a neuroanatomical and translational lens. We characterize their physiological parameters, clinical operational definitions and underlying brain networks, with particular attention to the extent of cortical involvement. Across fixation, pursuit and saccades, we show that cortical participation is frequent but does not necessarily imply conscious intention. We therefore propose reframing behavioural interpretation from a reflexive-versus-voluntary dichotomy toward a gradient of cortical mediation, aligned with the concept of Cortically Mediated State. We highlight the differential inferential strength of oculomotor behaviours: fixation may reflect subcortical stabilization, whereas pursuit and structured saccadic paradigms provide stronger evidence of cortical engagement. However, even cortically mediated eye movements do not constitute definitive proof of conscious awareness. Finally, we discuss methodological constraints in bedside assessment, the need for standardized oculometric paradigms, and the complementary role of multimodal approaches, including pupillary dynamics, to better disentangle preserved cortical processing from overt behavioural expression in severe brain injury.