Eye protection

Taken from Wikipedia.

Didymium (Greek: twin element) is a mixture of the elements praseodymium and neodymium. It is used in safety glasses for glassblowing and blacksmithing, especially when a gas (propane) powered forge is used, where it provides a filter which blocks the yellowish light emitted by the hot sodium in the glass, without having a detrimental effect on general vision, unlike dark welder's glasses. Blocked also is the strong ultraviolet light emitted by the superheated forge gases and insulation lining the forge walls thereby saving the crafters' eyes from serious cumulative damage.

Eye protection

Eye protection is an essential consideration when using propane to make glass beads. There are 2 reasons for this; firstly the glass bead is actually virtually impossible to see if you do not have the correct eye wear on. Secondly, if you do not wear appropriate eye protection over time your vision will be affected.

Eye protection comes in different forms depending on the glass that you are using, didymium glasses used for soft glass like Effetre will not be adequate for borosilicate glass.