So, today I rode to work wearing the dollar store safety glasses. I didn't have any problems with the sweat because it was a cool 50 degrees in the morning and the helmet was able to absorb whatever sweat I produced. No problem with visibility also because they have transparent glass on the sides as well.
However, the glasses would fog up every time I stopped at a traffic light. Do I really need to invest in good riding glasses to stop my whining?