I have just read a 280 page document. It was sent to me as a pdf. and I couldn’t print out all 280 pages, think of the cost and the waste of paper. So the only option was to read it off screen.
I have worked out the best way to read off the screen and I will share it with you. Enlarge the font so that the A4 page fills the whole screen. In a pdf this is a zoom to 250%. This makes the font big enough to be able to read the page in a constant slow scroll. I keep the page moving, and it is comfortable reading at that speed, and font size. It means the document is readable without the constant pausing at the end of each page, and there is no eye strain as the font is large and enables you to sit away from the screen. Give it a try.