2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/109662Random scattering of light is what makes materials such as white paint, clouds and biological tissue opaque. We show that although light propagating in these media is diffuse, a high degree of control is possible as phase information is not irreversibly lost. Opaque objects such as eggshell or white paint focus coherent light as sharply as a lens when illuminated with a wavefront that inverts the wave diffusion. We demonstrate the construction of such wavefronts using feedback, achieving a focus that is 1000 times brighter than the diffusely transmitted light. Our results are explained quantitatively by a universal relation based on statistical optics.5 pages, 5 figures. Revised text and incorporated new experimental resultsDisordered Systems and Neural NetworksSoft Condensed Mattertext