A wearable device includes a substrate, at least one light emitting component mounted on one side of the substrate and configured to emit light on at least one optical wavelength band, and at least one lens disposed on an out-light side of the at least one light emitting component, where each lens corresponds to at least one light emitting component, and each lens is capable of reducing a divergence angle of light emitted by the at least one light emitting component corresponding to the lens.