Review View Mirror Auto Dimming

[nate704]

Those side mirrors and review view mirror are supposed to auto dim at night. However, I don't think my review view mirror is auto dimming at all while side ones do.
How can you check if they are dimming properly or not??

 

[TriKKyOne]

Easiest way to tell if your rear view is dimming (really any auto dimming mirror) is to look near the edges to see if the light is brighter when it reflects off that area.