Any comment that has been scrolled off the screen for 5 seconds is considered read. (If you scroll back, you can see that the text and border have turn from black to gray.) If you scroll to the bottom and stay there for 5 seconds, all comments are marked read.
Any comment that has been scrolled off the screen for 5 seconds is considered read. (If you scroll back, you can see that the text and border have turn from black to gray.) If you scroll to the bottom and stay there for 5 seconds, all comments are marked read.