Cosmetic process for caring for the skin, more particularly facial skin, in particular wrinkled skin, comprising: (i) a step consisting in applying to the skin a composition, especially a cosmetic composition, comprising, in a physiologically acceptable medium, at least 0.3% by weight, relative to the total weight of the composition, of a grafted polysaccharide polymer of formula: PS-(CO-NH-L-X)a(COOH)b in which PS denotes the basic backbone of a polysaccharide bearing the carboxylic acid groups; L is a linear, branched or cyclic, saturated or unsaturated divalent hydrocarbon-based group comprising from 1 to 20 carbon atoms, preferably from 2 to 10 carbon atoms, which may be interrupted with one or more non-adjacent heteroatoms chosen from sulfur, oxygen, or an -NH-, -COO-, -CONH-, -O-CO-NH- or -NH-CO-NH- group, said divalent group being optionally substituted with one or more groups chosen from hydroxyl, amine, thiol, carboxylic acid, amide and cyano groups; X denotes a photoactive group of azide or diazirine type; a denoting the content of COOH groups substituted with the group -NH-L-X; b denoting the content of unsubstituted free COOH groups; a being between 0.01 and 0.8; b being between 0.2 and 0.99 a + b = 1 (ii) a step consisting in exposing the skin to light radiation, preferably for at least 5 seconds. (i) a step consisting in applying to the skin a composition, especially a cosmetic composition, comprising, in a physiologically acceptable medium, at least 0.3% by weight, relative to the total weight of the composition, of a grafted polysaccharide polymer of formula: PS-(CO-NH-L-X)a(COOH)b in which PS denotes the basic backbone of a polysaccharide bearing the carboxylic acid groups; L is a linear, branched or cyclic, saturated or unsaturated divalent hydrocarbon-based group comprising from 1 to 20 carbon atoms, preferably from 2 to 10 carbon atoms, which may be interrupted with one or more non-adjacent heteroatoms chosen from sulfur, oxygen, or an -NH-, -COO-, -CONH-, -O-CO-NH- or -NH-CO-NH- group, said divalent group being optionally substituted with one or more groups chosen from hydroxyl, amine, thiol, carboxylic acid, amide and cyano groups; X denotes a photoactive group of azide or diazirine type; a denoting the content of COOH groups substituted with the group -NH-L-X; b denoting the content of unsubstituted free COOH groups; a being between 0.01 and 0.8; b being between 0.2 and 0.99 a + b = 1 in which PS denotes the basic backbone of a polysaccharide bearing the carboxylic acid groups; L is a linear, branched or cyclic, saturated or unsaturated divalent hydrocarbon-based group comprising from 1 to 20 carbon atoms, preferably from 2 to 10 carbon atoms, which may be interrupted with one or more non-adjacent heteroatoms chosen from sulfur, oxygen, or an -NH-, -COO-, -CONH-, -O-CO-NH- or -NH-CO-NH- group, said divalent group being optionally substituted with one or more groups chosen from hydroxyl, amine, thiol, carboxylic acid, amide and cyano groups; X denotes a photoactive group of azide or diazirine type; a denoting the content of COOH groups substituted with the group -NH-L-X; b denoting the content of unsubstituted free COOH groups; a being between 0.01 and 0.8; b being between 0.2 and 0.99 a + b = 1 (ii) a step consisting in exposing the skin to light radiation, preferably for at least 5 seconds.