But it did.
I first noticed that images from my front camera looked soft. I used normal cloth to wipe off any grease, but no avail. Using my naked eye, I noticed "scratches", and I thought to myself: gone case.
Using a macro lens - Samsung NX30 with 60mm in my case - I realised how bad it looked.
But all was not lost. After googling around, it appears the "scratches" are just the lens coating, and all I needed was toothpaste and cotton bud to remove the layer.