So I'm 16, and wear contact lenses to correct my vision (My prescription is -12, -14 roughly)
  I am having trouble reading the whiteboard in school even with the lenses  
  Are there some cheap reading glasses I can get that will improve my ability to see the board? Or do I need to visit the doctors so they can adjust my prescription?  
  I'm typically 10-20 feet away from the board depending on the classroom
  Read more: 
Reading glasses on top of contacts?