Can I have my thread back?

;
I've owned this eInk phone and Kindle for a few months now. I prefer the phone because:
1) The phone Kindle app can do Immersion reading (Audible synced to kindle books). The Kindle can't.
2) The Kindle is smaller than I realised but the phone is still more pocketable.
The phone's Chinese though, loaded with spyware. Blockable with a firewall but not to be relied on so I can't use it for much phone stuff.
However, after using this for a while I've noticed that I don't need to use my glasses with it, so long as the backlight is off. IS THIS NORMAL?! I don't have this experience with standard print size books.