(EN)A naphthopyran compound represented by the formula (I) wherein: n1, n2, p, m and q represent an integer; R1, R2 and R4, represent a group selected from halogen, -Ra, -OH, -ORa, -SH, -SRa, -NH2, -NRaRa1, -NRbRc, -CO-Ra, -CO2Ra1, -OC(O)-Rd, -X-(Re)-Y, linear or branched (C1-C18) perfluoroalkyl group, wherein Ra, Ra1, Rb, Rc, X, Y, Re, and Rd are as defined in the description; Z represents a group selected from CO, CS, SO, SO2, CO2, C(O)S, CS2, C(O)NH, C(O)NRa, C(S)NH, C(S)NRa and C=NRa; R3 represents a group selected from halogen, -Ra, linear or branched (C1-18) perfluoroalkyl group -OH, -ORa, -SH, -SRa, -NH2, and -NRaRa1; R6 represents a group selected from -Ra which may be optionally substituted, linear or branched (C1-18) perfluoroalkyl, cycloalkyl, heterocycloalkyl, aryl, and heteroaryl, which may be optionally substituted; R5 represents a group selected from: halogen, -Ra, linear or branched (C1-18) perfluoroalkyl group, -OH, -ORa, -SH, -SRa, -NH2, -NRaRa1, -CO-Ra, -O-C(O)-Ra and -CO2Ra1; or when q is equal to 2, then two R5 together represents further a group -O-(CH2)q1-O- wherein q1 represents an integer comprised from 1 to 3 inclusive