I'm a visually impaired (i.e. partially sighted) person with some reading vision unless in direct sunlight, and that too only from a short distance of about six inches at most!
I'm a student of mathematics.
In order to read electronic books (ebooks), I use WinDjView for .djvu files, Adobe Acrobat Reader for .pdf files, and Epub Reader for .epub files on my Windows-based desktop PC.
I'm nowadays using Windows 8.1 on a Dell PC and have the High Contrast (Black) enabled.
In WinDjView and Adobe Acrobat Reader, I've also turned on the relevant settings so as to enable me to view my ebooks as white (or light-colored) text against a black (or dark-colored) background.
Without this sort of customization, I find viewing the computer screen extremely inconvenient.
In order to be able to read "on the go", I'm now looking for a device such as the Samsung's Galaxy Tab A (10.1'). Please visit the following URL for more information about this product.
However, I'm not aware of any Android-based DJVU+PDF+Epub reader software program that offers the High Contrast (Black) or a similar option. Is there any such program? Is there any free app with this feature? What about EbookDroid?
The reason why I'm not in favor of getting myself a laptop is the disadvantage for me while using a laptop because of the too close proximity of the screen with the keypad.