From quantum physics to cosmology, researchers aim to see things which are typically invisible – be it the entanglement of two particles or infrared signatures from space. In these and various other fields, we are confronted by a common challenge: What we can see with our own eyes or observe using standard optical imaging systems is limited to a small fraction of the information that the detected light actually carries. Two-dimensional (2D), flat images, such as a photo, only reveal the intensity and visible color of the light coming to us from an optical scene. However, light contains a wealth of information on the three-dimensional (3D) position, angle of incidence, spectral content, amplitude, phase, polarization, optical angular momenta, and coherence, amongst others. In fact, if light interacts with media, nature will give us structured light that is spatially varying in the named properties in a fashion that depends on the interaction. In this talk, I will present how we can use these kinds of structured light fields to extract information from an optical scene and, vice versa, how structured light can serve as an excitation or probing tool to gain access to usually invisible information. In this context, we will explore “optical vortices” in phase and polarization, their generation, and application. Moreover, we will gain insights into the nanoscale and quantum features of structured light and its leading role for next-generation imaging and sensing techniques.