I have a closet with a window and I want to let a little light come through the closet wall into the bedroom for light and for design.

I want to install 5 or 6 single blocks between the studs in the drywall. One side of the wall is plasterboard, the other side is open and I will finish with drywall. How do I install a single block in the wall...it will look like 5 separate 8 inch portholes or windows?