In a Google+ posting, the company says that current Google Glass wearers known as 'Explorers' will be able to trade in their existing headsets for a new model and that they will each also be entitled to invite three friends to join the program.

The next version of Google Glass will be compatible with prescription lenses for those people that have no choice but to wear glasses and it will also be doing away with the bone conduction speaker system in the current model, which many users have claimed is rather less than good. However, it is being replaced by a single ear bud, which means one-ear mono sound great for making a phone call but not for listening to music.