an illumination device that includes at least two concentrically mounted cylinders mounted within the narrower cylinder is at least one light source . the cylinders are mounted such that at least one of the cylinders may be selectively rotated , by a user , about the common axis of concentricity relative to the other cylinder . each of the cylinders further includes sections which extend along the long axis thereof , at least one of which is completely opaque and at least one of which is either semi - translucent , completely translucent , or entirely transparent . the sections of various opacities are sufficiently and appropriately sized such that , by corresponding alignments thereof , by the selective relative rotation of the cylinders , the light source within the nested cylinders may alternatively provide illumination , or be effectively covered without requiring the active turning on or off of the light source .