[T1M] Is there a backlight?

Yes, there is backlight that is automatically trigged when the light sensor detects a dark environment.  Once turned on, the backlight will remain on for 30 seconds before it attempts to check the light again.  

You can manually force the backlight on by holding your finger over the ambient light sensor (the two slits at the edge of the display glass) and moving the tape measure blade (with the device turned on).