Laminated Glass
This is the way that the windscreens of modern cars are manufactured and its advantage it that it is inherently much stronger than conventional glass and cannot shatter. Typically it is composed of 3 layers, two outer layers of glass with an intermediate layer of plastic, all thermally bonded together.

The glass we use in the Scorpion TGX is made in this way, here in Great Wyrley, to the best of my knowledge and belief circular torch or lamp glasses made in this way are not obtainable. If they were, I would not be making them myself would I?

There are no adhesives used, the bonding is by compression of the three layers and raising the temperature in order to obtain a partial melting of the plastic inerlayer.

This is true laminated glass and should not be confused with "multilayer" or "coated" glass.

Also in common with modern windscreens the glass is direct bonded to the lamp face plate using a special compound.

I have tested these glasses by striking them with rounded end of a ball hammer while lying on a carpet and was unable to break the glass. The fitting to the lamp is done in such as way as to surround the glass with a protective aluminium ring, the completed assembly is far stronger than will be needed in any kind of foreseeable use. The wearer will break before the lamp does.