Light switches are not working, all outlets are

I woke up this morning and realized that none of the light switches in my home are working, however all outlets are still working. I checked the breaker and nothing was tripped, then I went ahead and reset the breaker just to insure that that was not the problem.

The only other information I have to offer is that I changed a three-way switch in my home yesterday however, it worked throughout the rest of the day.