Progressive Mirror (video) The Optical Society Loading video... Caption This video demonstrates how the progressive mirror provides an accurate depiction of the distance to approaching-from-behind vehicles. The appearance of the vehicle out the side window just as it leaves the mirror's field of view demonstrates the smooth transition between zones and the elimination of the blind spot. Credit Optics Letters. Usage Restrictions None Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.