Currently, there are mainly three types of clip on sunglasses, namely standard clip on, flip up clip on and magnetic variants. The standard form clip-on sunglasses have a clip at the center of the bridge and fasten onto prescription glasses over the same spot. In other words, such a clip on has a claw that hooks to the regular prescription frame. Flip up clip on sunglasses use a magnet to attach to a prescription frame, so that they are sometimes called magnetic flip-ups. The third type is magnetic clip on sunglasses. This form has invisible magnetic clips which can fasten along the sides of prescription eyeglasses. With the magnetic feature, these clip ons are easy to use and they just “click†into the right place.