A hinge mechanism for an eyewear device, the hinge mechanism comprising: a pair of hinge pieces (208; 211), each of which comprises: a hinge formation (312; 402) that is hingedly engaged with a complementary hinge formation (312; 402) of the other hinge piece, the engaged hinge formations (312; 402) defining an internal hinge cavity that is hidden from external view and permitting hinged movement about a hinge axis, the hinge axis coinciding with the hinge cavity; and a body portion (244; 309) fixedly attached to the respective hinge formation, the body portion (244; 309) defining a passage (239; 259) that extends therethrough and that is in communication with the hinge cavity; and a conductor that extends through the passages of the respective hinge pieces (208; 211) and through the hinge cavity, such that the conductor is obscured from external view at the engaged hinge formations (312; 402), wherein the conductor is capable of intersecting the hinge axis within the hinge mechanism; wherein the hinge formation (312; 402) of one of the hinge pieces (208; 211) comprises a pair of tubular end knuckles that are co-axial with the hinge cavity and that are located at opposite axial ends of the hinge cavity; wherein the hinge mechanism further comprises a pair of hinge pins pivotally connecting the complementary hinge formation (312; 402), the pair of hinge pins being located in the pair of end knuckles to close off opposite axial ends of the hinge cavity, and wherein at least one of the passages (239; 259) through the body portions (244; 309) opens axially into the hinge cavity, such that the conductor extends: transversely through a first one of the hinge pieces (208; 211); axially into the hinge cavity; and from there transversely through a second one of the hinge pieces (208; 211). a pair of hinge pieces (208; 211), each of which comprises: a hinge formation (312; 402) that is hingedly engaged with a complementary hinge formation (312; 402) of the other hinge piece, the engaged hinge formations (312; 402) defining an internal hinge cavity that is hidden from external view and permitting hinged movement about a hinge axis, the hinge axis coinciding with the hinge cavity; and a body portion (244; 309) fixedly attached to the respective hinge formation, the body portion (244; 309) defining a passage (239; 259) that extends therethrough and that is in communication with the hinge cavity; and a hinge formation (312; 402) that is hingedly engaged with a complementary hinge formation (312; 402) of the other hinge piece, the engaged hinge formations (312; 402) defining an internal hinge cavity that is hidden from external view and permitting hinged movement about a hinge axis, the hinge axis coinciding with the hinge cavity; and a body portion (244; 309) fixedly attached to the respective hinge formation, the body portion (244; 309) defining a passage (239; 259) that extends therethrough and that is in communication with the hinge cavity; and a conductor that extends through the passages of the respective hinge pieces (208; 211) and through the hinge cavity, such that the conductor is obscured from external view at the engaged hinge formations (312; 402), wherein the conductor is capable of intersecting the hinge axis within the hinge mechanism; wherein the hinge formation (312; 402) of one of the hinge pieces (208; 211) comprises a pair of tubular end knuckles that are co-axial with the hinge cavity and that are located at opposite axial ends of the hinge cavity; wherein the hinge mechanism further comprises a pair of hinge pins pivotally connecting the complementary hinge formation (312; 402), the pair of hinge pins being located in the pair of end knuckles to close off opposite axial ends of the hinge cavity, and wherein at least one of the passages (239; 259) through the body portions (244; 309) opens axially into the hinge cavity, such that the conductor extends: transversely through a first one of the hinge pieces (208; 211); axially into the hinge cavity; and from there transversely through a second one of the hinge pieces (208; 211).