It detects the surrounding light thrue the camera and adjusts the visibility
settings/brightness
Your settings on your iPod Touch are set to a lower brightness than other iPod Touches. Go to Settings, and then General, and sift through there (usually under 'display') and you should find brightness, and you can adjust the brightness of your iPod touch from there.
Save battery
turn the brightness low
Yes, it will. The higher the brightness. the less the battery life will be.
I'm pretty sure it's for the light on the Auto-Brightness thing on your iPod. I have that hole on my own iPod case and I also did the research. ;) Hope that helped!
The dot is actually purple but its a light sensor for the auto-brightness setting it is normally very hard to see unless in strong or direct sunlight and it changes the brightness if your outside or inside.
It is a light sensor. It increases or reduces the brightness of the backlight judging by the light you are in. For example, if you are outside on a bright sunny say, the brightness would increase so you could see it better. If you were to be in a pitch black room, the iPod Touch would reduce backlight so you don't waste as much battery power while you can still see the screen.
yes, it does, but it doesn't affect the battery too much.
No
Simply click the settings app on your iPod Touch, then go to the brightness section. There is a button in which you can slide from left to right to make dimmer or brighter.