Abstract: The intrinsically photosensitive retinal ganglion cells (ipRGCs) are the main photoreceptors of the non\|image\|forming visual functions, and are responsible for regulating biological rhythm activities, such as sleep awakening and hormone secretion. Glaucoma, as a type of disease that characteristically damages retinal ganglion cells, can also lead to the damage of the ipRGCs and related visual pathways, and affect the reception and entrainment of light signals. The proportion of patients with damaged non-|image\|forming visual functions which regulated by ipRGCs is significantly increased in glaucoma patients, including sleep disorders, abnormal hormone secretion and decreased pupillary light reflection function, etc. These findings of glaucoma and biological rhythm further enrich the understanding of clinical diagnosis and treatment of such diseases. (Int Rev Ophthalmol, 2020, 44:145-149)