Mood disorders mainly refer to depression and bipolar disorder， which often occur in early adulthood and are one of the main causes of social dysfunction and disability in young adults， causing a huge economic burden on society. Patients with mood disorders have multiple functional impairments， but their functional impairments are difficult to quantify and may manifest differently at different stages of the disease， potentially affecting their lives and even causing serious adverse consequences such as self-injury and suicide. Eye tracking technology is an objective evaluation method for a series of spontaneous， controlled， and purposeful movements of the eye. It has the advantages of lightweight instruments， relatively simple operation， and non-invasiveness， and is increasingly widely used in the field of psychiatry. This article summarizes the current eye tracking research related to mood disorders， focusing on the eye tracking paradigms that can be used in clinical practice， potential clinical application directions， the potential of multimodal analysis， and the development direction of eye tracking technology. It explores the potential of eye tracking technology as a functional assessment tool for patients with mood disorders， to provide reference for clinical applications.