Cameras for filming or photography will become ever smaller, lighter, and compacter. Besides often being integrated in other devices, e.g. in smartphones, such cameras, as miniature systems, are used in medicine, for example in endoscopes. Almost all applications require that the user can adjust the focus automatically or manually. The adjustability of the camera focus is currently achieved by means of a system of several lenses with variable distances. In the case of telephoto lenses, for example, the photographer changes the focus by sliding the lens in or out and thus varying the distance of the lenses from one another. The drawback of that kind of focusing is that such variable lens systems require relatively much space. Researchers from KIT's Institute of Applied Computer Science (Institut für Angewandte Informatik - IAI) work on an artificial lens system for the human eye that automatically focuses on near or far objects. Research into such kind of artificial accommodation system comprises the development of a lens system whose focus can be adjusted by turning. The refractive power and hence the focus of a lens depend on the lens thickness, the curvature of surfaces, and the refraction index difference of the materials. The system conceived at KIT consists of two lenses with a plane and curved surface each. Whereas the two plane sides touch each other, the curved surfaces face outwards. Since the curvatures of the lens surfaces, unlike those of conventional optical systems, are not axially symmetric to the optical axes but helical instead, the refractive power can be varied by turning the lenses. Such turnable lens arrangements require much less space than conventional optical systems. The KIT-developed devices thus are advantageous wherever compactness is paramount. In addition to being used as cameras in smartphones, the systems for example could be used in miniature projectors or surveillance cameras.