The invention relates to a glazing unit comprising a substrate coated with a variable light scattering system switching between a transparent state and a translucent state comprising a scattering layer able to scatter the incident light along scattering angles greater than the critical total internal reflection angle at the interface between the substrate and the air and at least one pair of elements absorbing visible light separated from one another at least by the scattering layer. The invention also relates to the use of said glazing unit as a projection or back-projection screen.