You can read official features of Lumia 830 display below.
Display features: Brightness control, Nokia Glance screen, Sunlight readability enhancements, Corning® Gorilla® Glass 3, Easy to clean, High brightness mode, Lumia Color profile, Sculpted glass, Wide viewing angle, Double-tap to wake
So, in this video, we tried to test outdoor or sunlight readability of Lumia 830 display and check how wide the viewing angles are on a sunny day, outdoors. Well, seems Lumia 830’s display is perhaps the best you will see on a mid-ranger. It has great sunlight readability and viewing angles are very wide outdoors, even on a bright sunny day