In 1655, a British scientist Robert Hooke published Micrographia based on the world he saw with a microscope, marking the start of cell-scale research into biological phenomena. During the 19th century, the gradually mature optical microscopic imaging played a significant role in biological investigations with the development of electromagnetism and precision manufacturing technology. Due to the surge of new technologies like laser, digital lasers and gene editing, optical imaging in biology experienced rapid development in the 20th century with various new imaging methods coming out as well as technological and physical limits being broken. Nowadays, optical imaging has become one of the indispensable methods when investigating life sciences. This lecture is a review of the development of optics in the observation of biological phenomena and the opportunities and challenges it comes across in present and future. A wonderful world created by the collisions of physics and life sciences and of science and art is to be shown to you.