recycling – What kind of lenses used for eyewear doesn’t melt in the oven? – GWC Mag

I suspect anything made from plastic could be damaged, but true glass lenses should be fine.

Borosilicate glass, used in optics, has a glass transition temperature of 500 degrees Celsius. Because the glass transition is not a strict melting point but rather the material becomes softer at around that temperature, you don’t want to go anywhere near it. But 130 degrees Celsius should be safe.

So buy true glass lenses and you should be fine.