A liquid crystal medium comprising one or more polymerisable compounds of formula I P-Sp-A 1 -(Z 1 -A 2) z -R b I wherein the individual radicals, independently of each other and on each occurrence identically or differently, have the following meanings P a polymerisable group, Sp a spacer group which is optionally substituted by P, or a single bond, A 1, A 2 benzene or naphthalene, which are optionally substituted by one or more groups L, L 9, L 10 or P-Sp-, Z 1 -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, -OCH 2 -, -CH 2 O-, -SCH 2 -, -CH 2 S-, -CF 2 O-, -OCF 2 -, -CF 2 S-, -SCF 2 -, -(CH 2) n1 -, - CF 2 CH 2 -, -CH 2 CF 2 -, -(CF 2) n1 -, -CH=CH-, -CF=CF-, -CH=CF-, -CF=CH-, -C≡C-, -CH=CH-CO-O-, -O-CO-CH=CH-, -CH 2 -CH 2 -CO-O-, -O-CO-CH 2 -CH 2 -, -CR 0 R 00 -, or a single bond, R 0, R 00 H or alkyl having 1 to 12 C atoms, R b F, Cl, -CN, P-Sp- or straight chain, branched or cyclic alkyl having 1 to 25 C atoms, wherein one or more non-adjacent CH 2 -groups are optionally replaced by -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O- in such a manner that O- and/or S-atoms are not directly connected with each other, and wherein one or more H atoms are each optionally replaced by P-Sp-, F or Cl, L 9 F or Cl, L 10 -CH 2 -O-A, A alkyl with 1 to 6 C atoms, L F, Cl, -CN, P-Sp- or straight chain, branched or cyclic alkyl having 1 to 25 C atoms, wherein one or more non-adjacent CH 2 -groups are optionally replaced by -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O- in such a manner that O- and/or S-atoms are not directly connected with each other, and wherein one or more H atoms are each optionally replaced by P-Sp-, F or Cl, z 0, 1, 2 or 3, n1 1, 2, 3 or 4, characterized in that the compounds contain at least one group A 1 or A 2 that is substituted by at least one group L 9, and at least group A 1 or A 2 that is substituted by at least one group L 10, wherein the groups L 9 and L 10 may be attached to the same or different rings A 1 or A 2. P a polymerisable group, Sp a spacer group which is optionally substituted by P, or a single bond, A 1, A 2 benzene or naphthalene, which are optionally substituted by one or more groups L, L 9, L 10 or P-Sp-, Z 1 -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, -OCH 2 -, -CH 2 O-, -SCH 2 -, -CH 2 S-, -CF 2 O-, -OCF 2 -, -CF 2 S-, -SCF 2 -, -(CH 2) n1 -, - CF 2 CH 2 -, -CH 2 CF 2 -, -(CF 2) n1 -, -CH=CH-, -CF=CF-, -CH=CF-, -CF=CH-, -C≡C-, -CH=CH-CO-O-, -O-CO-CH=CH-, -CH 2 -CH 2 -CO-O-, -O-CO-CH 2 -CH 2 -, -CR 0 R 00 -, or a single bond, R 0, R 00 H or alkyl having 1 to 12 C atoms, R b F, Cl, -CN, P-Sp- or straight chain, branched or cyclic alkyl having 1 to 25 C atoms, wherein one or more non-adjacent CH 2 -groups are optionally replaced by -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O- in such a manner that O- and/or S-atoms are not directly connected with each other, and wherein one or more H atoms are each optionally replaced by P-Sp-, F or Cl, L 9 F or Cl, L 10 -CH 2 -O-A, A alkyl with 1 to 6 C atoms, L F, Cl, -CN, P-Sp- or straight chain, branched or cyclic alkyl having 1 to 25 C atoms, wherein one or more non-adjacent CH 2 -groups are optionally replaced by -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O- in such a manner that O- and/or S-atoms are not directly connected with each other, and wherein one or more H atoms are each optionally replaced by P-Sp-, F or Cl, z 0, 1, 2 or 3, n1 1, 2, 3 or 4,