adding prescription lens to Eachine EV100 goggles

I wanted to add prescription lens to my Eachine EV100 Goggles
I have printed this cutting maker
I took an old PLASTIC prescription lens with a close diopter to my current prescription.

I have found the estimated center of the lens and marked it with a marker. then I draw on the lens the cutting border with the 3d part.

after that, I have used a grinder to grind the lens to the marked borders.

After washing the lens from the plastic dast ' i have pushed the lenses to the goggles, and f