How E Ink Front Lit lighting Technology works and can help to protect your eyes
Front Lit Reading Front Lit eReader screen use edge-LED lighting with a diffusor layer (Light Guide) to spread the light evenly. The E INK eReader is not a Backlit Display (LCD). The LEDs in the E INK eReader do not shine light directly in the eyes: the LEDs shine from below the screen towards the top end of the screen. As it exits the LEDs, light is reflected inside a light guide from which it exits towards the display from specific holes, much like a leaky fiberoptic cable. The directionality and position of the LEDs, and the existence of the light guide, are precisely the differences which make the E INK eReader unlike a Backlit Display (LCD Tablets).
This Chart explains by itself.