(Obviously not sponsored/compensated by Crizal. I have a strict code of ethics.)
So about a week ago I ordered some eyeglasses based on my prescription for enlargement/reading (tuned to my eyes) and also got the Crizal Prevencia included with the lenses. When I first tried them last week I had pain in my right eye but it went away after a day (was bad but I was probably getting used to them. My right eye has nystagmus/lazy eye and everything is smaller compared to left eye)
I started using them fully at the beginning of the week (Monday) and what can I say? It makes a huge difference to me. I start working on my computer (dual monitors, Macbook Pro 15 and BenQ 27 inch) around 9 AM and normally my eyes feel tired and "done for the day" by noon. Not so for these glasses. I can keep going all day with no problems.
In fact I haven't felt this good in four years and started to feel what @Slacor feeled after his "recovery" from his severe eyestrain and headaches. Let me tell you, it's glad to be back.