The tiniest e-reader in the world, and you can build one yourself
androidauthority.com
androidauthority.com
If there are only four words per line, you can slide your eyes down the middle and take in all the words in a chunk like you would for normal speed-reading.
I have an xteink X4 and X3 and I swear I can read for much longer without strain. You can also just crank your margins way up on most other e-readers.
The original Openbook and the Abridged version haven't been active projects in a while.
I got mine from some random guy on the discord who happened to have a bunch of kits he found in his closet or something.
https://www.reddit.com/r/myog/comments/1sa2710/temperatus_my...
A recent article on HN convinced me to try the M5Stack Paper S3. Much nicer screen with 16-level grayscale touchscreen, microSD slot, ESP32-S3 with WiFi and Bluetooth, supports the Crosspoint Reader software. It's got a magnetic back but won't fit on the back of a Magsafe phone like the Xteink4 can. It's double the price, but well worth it.