The Invisible Blinds cover your windows to actively keep sunlight out in the summer and let more in during the winter. Without any power source, the blinds are able to regulate the light streaming into your abode. All you have to do is place it over your window and let it do its magic.
Invisible Blinds were designed by researchers at the National Institute of Advanced Industrial Science and Technology in Japan and Sumitomo Chemical Co Ltd. The blinds work by using a special surface to block light from certain angles out. Sunlight has a high incidence angle during the summer and a low incidence angle during the winter. As a result, the blinds are able to passively block out light from certain angles.