Since the time Robert Propst concieved the idea of the cubicle to give the employee more space as well as privacy in order to increase the productivity, the entire concept of the cubicle has changed since then.
It has become more congested and ofcourse the concept of privacy doesn't even apply to cubicles that we find these days in offices.
With too many people working in a windowless cabin, cramped with cubicles, there is ofcourse no chance that you might get anything but artificial light on your desk and this prolonged exposure to artificial light has been found to be a harbinger of diseases like cancer, diabetes and mostly eye problems.