A photochromatic composition, endowed with a high light fatigue resistance contains a photochromatic compound belonging to the class of spirooxazines and an U.V.-stabilizer consisting of a sterically hindered amine to be defined by means of formula (I): ##STR1## wherein: R is either hydrogen or a methyl group,x is either oxygen or nitrogen,m is a number comprised within the range of from 2 to 10, andn is a number coprised within the range of from 1 to 100.A photochromatic article made from a thermoplastic material, endowed with a high light fatigue resistance, contains a thermoplastic material and the hereinabove disclosed photochromatic composition.