Here is an adapter I created to allow prescription inserts be installed on a set of pit vipers.

You will have to take the nose piece off then place the RX inserts inbetween the lense and the adapter.

The prescription inserts we had were some cheap prescription glasses we got from goggles4u. Took them apart, bent them slightly and clipped the nose pieces. You can try with the nose pieces on first.

We used the following:
https://www.goggles4u.com/g4u/browline-eyeglasses-145152-c.html

It looks to be out of stock but this other one looks like it will work too.
https://www.goggles4u.com/g4u/browline-eyeglasses-145440-c.html

Printed with 100 percent infill.