The Vl53l0x is what's known as a time of flight sensor.
This sensor can measure a distance using a laser!

However these sensor are well..  sensitive and can detect a transparent visor pretty easily.
As it is usually not possible to place the sensor directly against the visor I made an adapter that allows you to have the sensor as close to the visor as possible without physically being attached or touching it.
I have included a premade version which slots directly into the existing JtingF Protogen helmets and should instantly be positioned and alligned without breaking a sweat.

The theory behind this part is to reduce/avoid crosstalk between the laser and the receiver.
In this solution the goal is achieved by having both sensors separated physically.
However just separating them in this use case isn't enough due to there not being a physical connection to the visor, thus leaving an air gap.
So in addition to that both “tunnels” are of different length and exit shape.
This forces the light sources both in and out to exit/enter at a different angle.
And this forces them apart eliminating crosstalk and forcing the light through the visor. 
Now you can get accurate readings as if the visor was never there to begin with.

This project uses 2x m3 heat set inserts (ruthex style).

I have included the STEP files for easier editability.
Feel free to use this model for any project you like, be sure to give proper credit when using it.