Darkness is a familiar natural phenomenon, and it is also the foundation for many symbols and metaphors in language. However, comparative studies of perceptual metaphors related to "黑暗/darkness" in Chinese and Vietnamese are still limited. Based on the theory of perceptual metaphors, this study analyzed and compared the usage of "黑暗/darkness" in the two languages. The results show that, in addition to the original meaning of the phenomenon of lack of light, both generalize "darkness" into many abstract conceptual domains; Chinese often leans towards socio-political contexts, while Vietnamese emphasizes images rich in emotions, associated with personal experiences. These findings not only complement the metaphorical study of perception but also contribute to elucidating the cohesive relationship between language, culture, and how people perceive the world.