The invention relates to a capsule comprising a shell containing a transparent and thermally conducting liquid, particles having a thermochromic coating and particles having a photochromic coating, the thermochromic particles being bulkier than photochromic particles, the liquid being such that, within a first range of temperatures, its density is greater than the density of the thermochromic particles and than the density of the photochromic particles, and such that, within a second range of temperatures greater than those of the first range, the density of the photochromic particles is less than the density of the liquid, which is itself less than the density of the thermochromic particles.

The invention relates to a capsule comprising a shell containing a transparent and thermally conducting liquid, particles having a thermochromic coating and particles having a photochromic coating, the thermochromic particles being bulkier than photochromic particles, the liquid being such that, within a first range of temperatures, its density is greater than the density of the thermochromic particles and than the density of the photochromic particles, and such that, within a second range of temperatures greater than those of the first range, the density of the photochromic particles is less than the density of the liquid, which is itself less than the density of the thermochromic particles.

Coating with photochromic properties, method for producing said coating and use thereof applicable to optical articles and glazed surfaces. The coating is formed by the combination of the following three elements: (1) a polymeric matrix, which is typically rigid and deposited on the surface of interest; (2) hollow, sealed micro- and/or nanocapsules dispersed within said matrix; and (3) solutions of photochromic compounds (chosen from a group comprising spirooxazine, azobenzenes or chromenes) in a liquid solvent that does not react (with the photochromic compound and with the capsule wall), which are encapsulated inside said micro- or nanocapsules.