Explore advanced concepts in optics and electromagnetic waves in this lecture from the "Light and Beyond" summer course series. Delve into topics such as lateral waves, inhomogeneous and anisotropic media, mirages, and the Huygens-Fermat principle. Learn about ray curvature, optical analogies, and the historical debate between Huygens and Newton. Engage with problem-solving techniques, including the Dijkstra algorithm for shortest routes. Suitable for undergraduate and master's students in science and engineering, this intensive course combines mathematical analysis, experimental demonstrations, and computer simulations to provide a comprehensive understanding of optical phenomena in nature and technology.