I feel that way with every x-ray I've ever had taken during my life. Its like, how exactly is that nebulous blobby grey area an indicator of a fraction, I've g

I feel that way with every x-ray I've ever had taken during my life. Its like, how exactly is that nebulous blobby grey area an indicator of a fraction, I've got no idea. I trust the doctors, I just don't see how its so damn visible every time. Like, they look for shadowy shapes with certainty and I just can't see them, myself.