A Rod lens is a special type of cylinder lens, and is highly polished on the circumference and ground on both ends. When the ends of rod lenses are polished they may be used as circular lenses, and will have the same optical properties as a long circular lens with a narrow diameter. These lenses have an important application in rigid endoscopes, medical instruments used to view inside the human body. Unlike a traditional microlens, a rod lens will self-align to the tube diameter. Their unique shape means they can also provide structural support to the endoscope tube. For endoscopy used precision cut lenses and exact surface curvature are essential. A series of optical elements such as a micro lens and rod lens are the core of endoscopic imaging. Changchun Yutai Optics Co., Ltd. manufactures rod lenses suited for endoscopic applications.