How to Fix the Lighting on the Kindleby William Pullman
The Kindle Fire was the first model in the line of e-book readers to have a backlit screen, joined since by the Fire HD and the Paperwhite models. A common problem with the backlight is that its current setting may make reading uncomfortable. The Paperwhite presents a second problem with the backlight in the form of uneven brightness along the margins of the screen.
About Screen Brightness
You can reduce eyestrain by adjusting the backlight based on the lighting in the room. In a bright room, increasing the Kindle's backlight makes the screen easier to read; but that same bright setting could bother your eyes in a dimly lit environment. Properly adjusting the screen brightness can improve your reading experience with the Kindle.
The Kindle Paperwhite's brightness setting is located in the toolbar, which you can view by tapping the top of the screen. The Brightness Control icon has the appearance of a light bulb. Tap this icon to view brightness control's vertical scale. Screen brightness is increased by moving your finger up the scale and reduced by sliding your finger down the scale. The Paperwhite backlight has a design flaw that causes uneven lighting along the margins of the page. Adjusting the backlight setting will not fix the lighting in the margins; this issue has no fix. In most cases, the lighting problem does not affect the text on the page.
Kindle Fire First Generation
The first-generation Kindle Fire has a brightness control in the Quick Settings menu. To access Quick Settings, tap the gear wheel icon, located next to the battery indicator in the Status bar. Tapping "Brightness" displays a horizontal slider control; slide the control to the right to increase brightness or to the left to lower the brightness.
Kindle Fire HD
The Kindle Fire HD has an automatic brightness feature that adjusts the screen light based on the ambient light of the room. If the screen brightness doesn't change when the lighting in the room changes, check that the sensor on the side of the screen isn't covered. To turn off the automatic brightness adjustment, swipe down from the top of the screen to display the Quick Settings bar, then tap "Brightness" and touch the "Off" switch. You can manually adjust the brightness of the screen by moving the slider under the switch.