The eyes bit in reference to an LCD tablet is a personal thing and varies from individual to individual. It bothers my eyes for prolonged reading (novels), but is fine for short attention span reading (magazine articles, web browsing).
I read my books exclusively on a Kindle Keyboard and refuse to read them on a tablet.
The advantages of an eInk ereader vs an LCD tablet are:
- smaller size -- easier to hold one handed
- much lighter weight -- 6~8oz vs 14~16oz (7") vs 21~26oz (10")
- much longer battery life: 15~30 hrs vs 7~10 hrs
- eyes bit: subjective, YMMV
And welcome to the board