This definitive focus contributes to a uniform, dark appearance when you scan the ceiling and the room itself. Computerization of the workforce has driven big changes in commercial lighting design. This was essential beginning in the 80 s, given the proliferation of computers in offices. The interstertial passage between a hard slab floor and the suspended ceiling plane is rarely more than 24 inches these days. You have little room left for bulky recessed lighting.
Parabolic fixtures fit the bill, being shallow in depth requirements yet powerful in lumen output.
The parabolic fixture was first designed for small individual offices, where its sharp cut-off created a nice clean look. But then offices went to the open layout we see everywhere today, with partition walls dividing space into individual work stations. Unfortunately, parabolic lighting causes a lot of shadows in cubicles. Workers have to compensate by using desk lamps for hand tasks, especially if they are assigned to cubicles without windows or other natural light sources. Time for a change You can sometimes have too much of a good thing.