Hi, I have been reading Mikes NEC book, 2005, and recently started the 2008 exam book. Both are excellent, but at the end of the work day it is hard to stay focused, both mentally and visually. Do any of you who have used the DVD's to the books think they help understand the material, or would be a good assist to understanding the books? Also, Mike is right about the eye strain issue. I did not think it would apply to me, but I am at that age were my vision is changing, and the words do get blurry. Thanks for the responses.