The new Nook's "N" button at the bottom of the device activates its GlowLight, a series of LED lights embedded in the product's frame around the screen, to illuminate its 6.5-inch E-Ink screen for reading in low-light or dark environments, Fox News reported Friday.
The brightness of the GlowLight can be adjusted to suit the reader.
Costing $139, the new unit has faster page-turning and longer battery life than the original Nook Touch, Barnes & Noble said, with up to 60 hours of continuous reading with the GlowLight turned on at 18 percent.
The new Nook also weighs 5 percent less than its predecessor at 6.95 ounces.
Barnes & Noble said its research found two-thirds of U.S. adults say they read in bed and 42 percent get annoyed when a partner reads in bed with the light on.