Glassing is a physical attack using a glass or bottle as a weapon. The most common method of glassing involves the attacker smashing an intact glass in the face of the victim.
For example, picking up a glass bottle, breaking off the neck and stabbing the victim with the broken bottle causing serious wounding or disfigurement: between three and 16 years custody, with a maximum of life imprisonment for the most serious cases.
The use of any glass object as a weapon in any assault is considered an aggravating feature. Charges for 'glassing' offences commonly range from Assault Occasioning Bodily Harm to Unlawful Wounding and Grievous Bodily Harm, depending on the injury a victim sustains.
It hurt. The back of the head is vulnerable to forceful strikes, whether a bottle strike or a fall. On the other hand, the frontal bone, your forehead, is quite strong. A very hard strike to the back of the head can easily result in cerebral hemorrhage and death.