A sideshade for reducing peripheral glare that is removably attachable to a temple of spectacles such that the wearer of the spectacles is not required to remove the spectacles in order to attach the sideshade to or detach the sideshade from the temple of the spectacles. The detachable sideshade is optical or near-optical quality so as not to degrade the wearer's peripheral vision. The sideshade may be light in weight and easy to attach and remove.