Here's how you can quickly adjust your screen brightness in iOS 7.
1. Swipe up from the bottom of any screen to access the Control Center.
2. Use the brightness slider to change your screen brightness to the preferred level.
3. Swipe down to get rid of the Control Center or just tap above it and it will disappear.
iOS 7 makes it very fast and easy to change your screen brightness with a swipe and a slide.