"30 fps flicker" - that's not a CRT, it doesn't flicker, because unlike CRTs, a flat display doesn't have a ray refreshing the display top to bottom.

And 30 fps on a CRT wouldn't be enough to produce stable image in the retina at all, which is why CRT TVs used to refresh at a minimum of 50Hz, and that still flickers (it stops "flickering" at around 75Hz).

With flat displays frame rate is about display responsiveness and animation detail.

So I wonder where are the claims about eye-strain coming from. Maybe because people just want better display responsiveness and they like to borrow from the problems low refresh CRTs used to cause, because it sounds scientific and legit as a problem.