At work, I stare at a computer screen all day. When I come home, I stare at the TV screen or my laptop; most of the time, I use both. The only time I’ve had a problem with eyestrain is when I wear contacts that get increasingly uncomfortable throughout the day.
IEEE spectrum ran an article yesterday on how the new iPad isn’t a threat to the Kindle because its screen is LCD rather than eInk — that the ease of reading eInk trumps reading on an LCD. As I was saying, I’ve personally never had any problems with eyestrain with a computer’s LCD. To that end, the Mayo Clinic says that eyestrain can be caused from not only extended computer use but also extended reading periods. If it isn’t clear yet, I think the whole eyestrain argument between LCD and eInk is bunk.
However, where I will praise eInk is in being able to read in sunlight. Washed out LCDs are a PITA whenever I use a gadget outside.