Abstract: In an optical guide, for instance a flexible optical cable, comprising at least two optical fibres and, surrounding the fibres, an outer protective sheath, each of at least some of the optical fibres has a continuous coating of a metallic material, e.g. aluminium or an aluminium-based alloy, which reduces the risk of surface damage of the optical fibre and also serves as an optical screen. At least one covering layer of non-metallic protective material, e.g. resin, enamel or plastics material, may overlie the metallic coating of each metal-coated optical fibre.