Custom Lens Holder for Headplay HD

I made a Lens Holder for my Headplay HD because the optical quality is not ok for me.
My left eye is "perfect" and has 0 Dioptin, right eye has + 1,0 Dioptrin.
I choose 60mm blank plastic eyeglasses with +7,5 Dioptrin for my left eye and + 8,5 Dioptrin for my right eye. I prepared the glasses on my cnc mill. You can find the example drawing for the left glass.

Examplecalculation for the lenses:
You are farsighted +2,5 Dioptrin
7,5 + 2,5 = 10,0

You are nearsighted -4,0 Dioptrin
7,5 - 4,0 = 3,5

The thickness of 4,1mm in the drawing was just for me to construct the lens holder. Never mind about this. It can also be 5mm or 8mm depends on your eyesight.
I used 4 screws M3x10mm