I've used both 13".3(1280x800) and 15" square(roughly around 1280x800) laptops(both widescreen). I recently sent back the 13" and am using the 15". I have excellent vision and I could read the text fine with no problems on the 13 inch, but I couldn't help feeling some kind strain. The strain wasn't that noticeable at all and I didn't notice this until I went back to the 15". With the larger print on a 15" I felt more relaxed or comfortable. I can't tell if it's it just in my head and psychosomatic(since I have excellent vision and never use reading glasses). Does anyone else notice a strain, even with excellent vision, from using a 13" screen?