(Redirected) Small circular holes under the screen

Hello Everyone,

I recently purchased a second-hand Venue Pro 11 7140.  I'm systematically scrutinising everything to make sure all is ok.  I was looking at the screen and I noticed 2 small circular holes under the bezel near the camera and one on the left, also under the bezel.  I'm not sure what they are: maybe they are sensors of some sort but I'd like to know before I decide to keep it.  I'm sure they are not mics as they are under the glass.  They look relatively equidistant so look official but I can't figure out what they are used for.  I'm hoping someone can shed some light on it as it were. 

peteatseti