Smart phone screen technology that is currently capable of producing a sharp visual quality and a wide color depth. Some of them are IPS screen technology on the iPhone, the Samsung AMOLED Super, and Super LCD from Sony. Each technology has advantages of each.
As an example in comparison AMOLED display and Super LCD screen. Second screen technology is also used on an Android phone Nexus One (only just a different screen). In the lab test results and circumstances outside in the daytime, the two-screen technology is almost equivalent, only the bright LCD screens give Super eyesight is better because it has high contrast.
However, in dark conditions / circumstances at night, seen the opposite. AMOLED display is still superior in dark environments, while also more comfortable to the eye. For more details, see the video comparison below (left, Nexus One with AMOLED screen vs. Right: Nexus One with Super LCD screen).