However, we shouldn't mess with light levels like these (or even somewhat lower ones) without some limits, and the main one is some automatic timing to turn things down after it gets too late. Otherwise you will find yourself staying at work later and later each day, and it's no accident.
Our clocks don't work that well with more than about a 14-15 hour photoperiod ("day"), so spending 18 hours under 5000 lux will screw up your overall rhythms, making your internal day longer than 24 hours and reducing your sleep. This is considerably worse if you're a natural night owl - it will make you later, faster.
The myth of electric lighting is that we can live in a permanent summer and turn the wintertime into summer, but there are important seasonal questions that we should think about too. For instance, cancer progresses much faster in summer than in winter [edit: cancer progresses much faster in constant light: winter vs. summer is complicated], and the winter schedule even engages a different part of the central clock in your brain than the summer schedule does. There are some important things going on here, which we've mostly tried to remove from our environments.
Knowing how the body works and having the capability to change it really do need to evolve in parallel - I think there is way more capability than knowledge right now.