Yea, I wish I could do paperbacks but the books I want are often not available in my country and shipping is a hassle so I settle for e-books and it hurts my eyes.
I find e-readers to be a pretty good compromise to reduce eyestrain. Older Kindles are pretty cheap here in the US at least and can side-load free ebooks (e.g. from project gutenberg.) (I guess Amazon may be removing that functionality in newer firmware so you may need to apply a jailbreak to prevent updates/prevent it from being removed.)