[dredmorbius]

Get a dedicated ebook reader if you can.

The price is pretty reasonable up to about 7-8", and not too high to 10".

I splurged for 13" as I read a lot and often low-quality scans of small, three-column print.

The pixel density of an ebook reader (200-300 DPI) is far higher than even Retina displays. Monocrome/greyscale gives higher resolution as well (the three-elements-per-pel aspect of colour displays means you're always left with about 30% the effective resolution, though subpixel aliasing helps a lot).

Portrait will display a single page well (laptop displays suck for reading text), and for larger devices or larger-print materials, you can often manage a two-page-up display.