I just purchased the Nook HD+, I only wanted it to use occasionally for pdfs and cookbooks, but not daily reading as my eyes also get tired from the color screens. I normally use an HP touchpad. However, surprisingly I've been able to easily read without strain, even very small text. Also, check out gaming glasses such as
http://www.amazon.com/Black-Gaming-E.../dp/B009OZYIA0 Just search amazon for "gaming glasses" There are several brands, you can often get them for about 20 bucks, they have good reviews for reducing eyestrain.