Plastic or rubber cones of various sizes are commonly used to set boundaries and designate dangerous or sensitive areas. For example, traffic or safety cones are used in traffic, construction, and accident settings to halt or direct traffic and passers-by. In sports, a smaller and lighter version of these cones is used to designate various boundaries such as the corners, and other portions of a playing field, including goal areas. Safety and sports cones are used during the day as well as nighttime, and visibility is a critical aspect of the cone. As a result, safety and sport cones are often given a highly noticeable, distinctive color such as bright orange or green. Moreover, some cones include a reflective material to be more visible when light is shined on them. However, in low-light conditions where the observer does not have the benefit of a directional light source (e.g. vehicle's headlights) to illuminate the cone, such as in nighttime sports activities, conventional cones may be difficult to see. It is desirable to have a cone that is highly and efficiently visible in low-light or no-light conditions.