Foscarini See You uses an innovative design to provide the maximum
from this lamp. Out of Its two polycarbonate lenses the inner one does
the direction of the light from the bulb. The outer lens does the
scatter to bring the best illumination to the room. At the same time
it is designed to give a decorative value too.
http://www.dmlights.com/en/cat/6626/0/foscarini/see+you.html