Rose didymium glass is the classic filter that was specially designed to absorb the bright yellow sodium flare at 589 nm, which occurs when heating glass. Spectacles with didymium glass protect your eyes from visible and UV light produced in the glass blowing and pearl making processes. Rose didymium enables the glass blower to look into the glass to be worked while it is being heated in the flame. In addition, the lenses have been hardened and thus also offer sufficient protection against any flying particles.