Microlenses have attracted considerable attention in the field of micro-/nano-optics due to their unique optical properties and simple structures, which allow them to be integrated into diverse optical systems to enhance optical performance. However, artificially fabricated optical microlenses face limitations in biocompatibility, biodegradability, and dynamic responsiveness. Natural biological optical microsystems provide inspiration for overcoming these constraints. It has been found that living cells and their microstructures exhibit lensing effects, functioning as natural dynamic optical components capable of performing optical functions within biophotonics research platforms. This paper analyzes biological microlensing techniques associated of algae, bacteria, red blood cells, and subcellular structures, and systematically summarizes their innovative application outcomes in key areas such as optical imaging, optical detection, optical manipulation, and optical transmission. Furthermore, the challenges and prospects for microlenses derived from living cells in the development of biophotonic devices are discussed.