Abstract: The present invention relates to binaphthyl compounds of the formula (I), which are suitable as monomers for preparing polycarbonate resins having beneficial optical properties and which can be used for producing optical lenses: Formula (I) where X is C2-C4-alkandiyl or C1-C4-alkandiyl-C(O)—, where C(O) is bound to the oxygen atom of the hydroxyl group and where C2-C4-alkandiyl or C1-C4-alkandiyl, respectively, are unsubstituted or carry a phenyl ring; R and R? are identical or different and selected from mono or polycyclic aryl having from 6 to 36 carbon atoms and mono- or polycyclic hetaryl having a total of 5 to 36 atoms, which are ring members, where 1, 2, 3 or 4 of these atoms are selected from nitrogen, sulfur and oxygen, while the remainder of these atoms are carbon atoms, where mono- or polycyclic aryl and mono- or polycyclic hetaryl are unsubstituted or carry 1 or 2 radicals Ra, which are selected from the group consisting of CN, CH3, OCH3, O-phenyl, O-naphthyl, S-phenyl, S-naphthyl, CI or F; and, if