The 455A has a magnifying power of 2.2 and can be used for precise viewing with the added 3.3 power lens. The exclusive clear-view lens has no center post to increase viewing. Shatter-resistant precision and optical lens bring the smallest detail up to a larger and sharper image. - The OptiVisor is a precision binocular head-band magnifier which permits unrestricted user efficiency while reducing eye strain. It comes with an adjustable headband and can be worn over regular glasses.