Photochromic naphthopyranes with the general formula or: wherein residues R 1, R 2, R 3, R 4, and R 5 respectively independently of one another represent a substituent selected from group α consisting of a hydrogen atom, a (C 1 -C 6) alkyl residue, a (C 1 -C 6) thioalkyl residue, a (C 3 -C 7) cycloalkyl residue that can have one or more heteroatoms selected from O or S, a (C 1 -C 6) alkoxy residue, a hydroxy group, a trifluoromethyl group, bromine, chlorine, fluorine, an un-, mono- or disubstituted phenyl-, phenoxy-, benzyl-, benzyloxy-, naphthyl- or naphthoxy residue, wherein the substituents can again be selected from group α; or two residues R 3 (if located in ortho position to one another) represent an unsubstituted, mono- or disubstituted annelated benzo-, pyrido, naphtho- benzofuro- or benzothieno-ring, the substituents of which can be selected from group α; n represents a whole number from 1 to 4, X and Y are selected independently of one another from the group consisting of -O-,-S-, -N(C 1 -C 6) alkyl, NC 6 H 5, -CH 2 -, -C(CH 3) 2 - and -C(C 6 (H 5) 2 -, residues R 6 and R 7 in the -CR 6 R 7 - grouping respectively independently of one another represent a substituent selected from group α, m represents a whole number from 1 to 4, or two or more adjacent -CR 6 R 7 groupings are part of an annelated benzo-ring, which can be un-, mono- or disubstituted, wherein the substituents thereof can be selected from group α, or X and/or Y together with the respectively adjacent -CR 6 R 7 grouping represent an annelated benzo-ring that can be un-, mono- or disubstituted, wherein the substituents thereof can be selected from group α, and B and B' independently of one another are selected from one of the following groups a) or b), wherein a) are mono-, di- and trisubstituted aryl residues, wherein the aryl residue is phenyl, naphthyl or phenanthryl; b) are unsubstituted, mono- and disubstituted heteroaryl residues, wherein the heteroaryl residue is pyridyl, furanyl, benzofuranyl, thienyl, benzothienyl, 1,2, 3,4-tetrahydrocarbazolyl or julolidinyl; wherein the substituents of the aryl or heteroaryl residues in a) and b) are those selected from the above-defined group α or from group χ consisting of amino, mono-(C 1 -C 6) alkyl amino, di-(C 1 -C 6) alkyl amino, mono- and diphenylamino un-, mono-disubstituted on the phenyl ring, piperidinyl, N-substituted piperazinyl, pyrrolidinyl, imidazolidinyl, pyrazolidinyl, indolinyl, morpholinyl, 2,6-dimethylmorpholinyl, thiomorpholinyl, azacycloheptyl, azacyclooctyl, un-, mono- or disubstituted phenothiazinyl, un-, mono- or disubstituted phenoxazinyl, un-, mono- or disubstituted 1,2,3,4-tetrahydroquinolinyl, un-, mono- or disubstituted 2,3-dihydro-1,4-benzoxazinyl, un-, mono- or disubstituted 1,2,3,4-tetrahydroisoquinolinyl, un-, mono-or disubstituted phenazinyl, un-, mono- or disubstituted carbazolyl, un-, mono- or disubstituted1,2,3,4-tetrahydrocarbazolyl and un-, mono- or disubstituted10,11-dihydrodibenz[b,f]azepiny1, wherein the substituent or substituents, independently of one another, can in turn be selected from (C 1 -C 6) alkyl, (C 1 -C 6)-alkoxy, bromine, chlorine or fluorine; or wherein two directly adjacent substituents of the aryl or heteroaryl residues in a) and b) represent a V-(CR 8 R 9) p -W grouping, wherein p = 1, 2 or 3, residues R 8 and R 9 respectively independently of one another represent a substituent selected from group α, and wherein V and W, independently of one another, can be -O-, -S-, -N-(C 1 -C 6) alkyl, -NC 6 H 5, -CH 2 -, -C(CH 3) 2 - or -C(C 6 H 5) 2 -, wherein two or more adjacent CR 8 R 9 units of this V-(CR 8 R 9) p -W grouping can be part of a benzo-ring annelated thereto, which can respectively in turn have one or more substituents selected from group α, or V and/or W together with the respectively adjacent CR 8 R 9 unit represent an annelated benzo-ring that can be un-, mono- or disubstituted, wherein the substituents thereof can be selected from group α. a) are mono-, di- and trisubstituted aryl residues, wherein the aryl residue is phenyl, naphthyl or phenanthryl; b) are unsubstituted, mono- and disubstituted heteroaryl residues, wherein the heteroaryl residue is pyridyl, furanyl, benzofuranyl, thienyl, benzothienyl, 1,2, 3,4-tetrahydrocarbazolyl or julolidinyl;