Where is the Light Sensor of Google Glass? The GDK document says that light sensor is available on Google Glass. But the document has no information about where the sensor locates on the Glass.

It seems that there are two possible positions:


In the front with the camera.
On the inner rim with the mysterious sensor which provides wink detection feature.


Anyone knows which is the source the Glass gathers light data?
From my reading it's a bit of both.

The Wink Detection uses a small light sensor. See here for a picture. Currently it seems that Google aren't releasing full code for this to be enabled, though libraries are available. The sensor in the GDK appears to be the Ambient Light sensor, beside the camera. 

According to the Google Glass Wiki the wink light sensor is just beside the display. 


  "Right next to the display is a tiny light sensor that watches your eyelid move. It's used for on-head and wink detection. If the sensor is obstructed or aimed incorrectly, these features will not work."


The camera has an ambient light sensor

Number 28 on the image below, from this article, is the ambient light sensor: