Similar to spontaneous emission of photons and inelastic (Raman) scattering, elastic (Rayleigh) scattering of light is controlled by spectraland spatial distribution of photon density of states, DOS (density of electromagnetic modes). However, to date Rayleigh scattering in nanoporous media has not become the subject of discussion in the context of photon DOS effects. In this paper, we consider light scattering in porous materials in the context of spectral, spatial, and angular redistribution of photon DOS in materials with pores whose size and spacing are of the order of light wavelength. The DOS effect results in predictable and controllable modification of scattering and can be purposefully used in certain light harvesting and illumination systems. A possible role of the effect in the cornea of eye is outlined for seeing at grazing incidence of light beams with respect to an eye pupil.Photon density of states, DOS (density of electromagnetic modes) appears in a number of formulas describing emission of photons by matter. First of all, it appears in the Plank's formula for spectral density of equilibrium (thermal) electromagnetic radiation. The density of equilibrium electromagnetic radiation is the product of photon energy, BoseEinstein distribution function, and photon DOS value. Second, photon DOS is known to appear in the expression for the lifetime of excited atoms, molecules, and solids since spontaneous emission of photons is viewed as stimulated emission with stimulating photons coming from zero-point oscillations of electromagnetic field. 1 Third, photon DOS can be found as a factor in formulas describing inelastic (Raman) scattering of photons by molecules and solids. 2 Finally, photon DOS factor is in the expression for the probability of elastic (Rayleigh) scattering of photons. 3 Similar to inelastic scattering, elastic scattering in terms of quantum electrodynamics is considered as virtual excitation of matter with subsequent photon emission. Elementary photon emission is considered as a result of interaction of an excited (actually or virtually) quantum system with electromagnetic zero-field fluctuations. Accordingly, the spontaneous emission rate, the probability of inelastic and elastic scattering of photons, is proportional to photon DOS. In a homogeneous space, the scattering rate W for photons with frequency ω into elementary solid angle dΩ reads where I(ω) is the incident photon flux, V is the matrix element for photon emission, and D(ω) is photon DOS. In a continuous medium, photon DOS D(ω) is expressed by the formula where c is the speed of light in vacuum and n is the refractive index of a medium under consideration (see, e.g., refs 1 and 2 and refs therein for more detail on DOS in various media). Noteworthy, the well-known ω 4 dependence of scattering probability, which is responsible for the blue sky color and sunset/sunrise redness, occurs essentially from the contribution of D(ω) in the form of eq 2. In complex media such as dense sols, matrices with pores, cavities, or inclusions ...