The role of TRPV4 channel present in human ciliary body epithelial cells in AANAT production was studied. AANAT, Aralkylamine N-acetyltransferase seems to be the key enzyme involved in producing melatonin from serotonin. In rodents, transcriptional activation of aanat gene is the classical mechanism to induce melatonin biosynthesis. TRPV4 is present in the human ciliary body and ciliary body epithelial cells. Activating TRPV4 channel increases the expression of AANAT, which elevates the concentration of NAS and melatonin