The present invention relates to a cosmetic or dermatological composition in emulsion form, comprising, in a physiologically acceptable support: a) at least one aqueous phase and b) at least one oily phase, and c) at least one merocyanine compound of formula (1 ) or one of the E/E- or E/Z- geometrical isomer forms thereof, in which: R is a C1-C22 alkyl group, a C2-C22 alkenyl group, a C2-C22 alkynyl group, a C3-C22 cycloalkyl group or a C3-C22 cycloalkenyl group, the said groups possibly being interrupted with one or more O, and d) at least one emulsifying system containing at least one gemini surfactant. Another subject of the present invention consists of a non-therapeutic cosmetic process for caring for and/or making up a keratin material, comprising the application, to the surface of the said keratin material, of at least one composition as defined above. The invention also relates to a non-therapeutic cosmetic process for limiting the darkening of the skin and/or improving the colour and/or uniformity of the complexion, comprising the application, to the surface of the keratin material, of at least one composition as defined previously. The invention also relates to a non-therapeutic cosmetic process for preventing and/or treating the signs of ageing of a keratin material, comprising the application, to the surface of the keratin material, of at least one composition as defined previously.La présente invention concerne une composition cosmétique ou dermatologique sous forme démulsion, comprenant, dans un véhicule physiologiquement acceptable : a) au moins une phase aqueuse, b) au moins une phase huileuse, c) au moins un composé mérocyanine de formule (1 ) ou lune de ses formes isomères géométriques E/E ou E/Z, dans laquelle : R est un groupe alkyle en C1-C22, un groupe alcényle en C2-C22, un groupe alcynyle en C2-C22, un groupe cycloalkyle en C3-C22 ou un groupe cycloalcényle en C3-C22, lesdits groupes étant interrompus par un ou plusieurs O, et d) au moins un
