A polarity checking apparatus for multi-fiber connectors includes a body, a diverging lens attached to the body and a screen attached to the body, wherein the apparatus is configured to determine test and/or determine polarity of the multi-fiber connector. The screen may be translucent or may be opaque in part and rotatable for checking whether a signal is being transmitted on an individual optical fiber position of the multi-fiber connector. The invention is also directed to a method for checking the polarity of an optical assembly.