A 26-year-old man has had emergency eye surgery after he was glassed at a bar in Murray Street.
The attack was one of two brutal assaults in the CBD street in the space of 45 minutes last night.
About 9.15pm, an argument broke out between the 26-year-old and a group of men at Carnegie's bar and restaurant.
The dispute escalated and the victim was struck in the face with a broken bottle.
The blow left him with a significant injury to his left eye which required overnight surgery at Sir Charles Gairdner Hospital.
A police spokeswoman said the attack "will result in permanent and significant sight damage".
Police have appealed for witnesses.
Less than an hour earlier, a 52-year-old Doubleview man was rushed to hospital after he was knocked unconscious on Murray Street.
The man was walking with his friends when one of them became involved in an altercation with a group of people nearby.
The 52-year-old man was punched in the face and fell to the ground unconscious.
He was taken to Royal Perth Hospital for treatment but police say his injuries are not life-threatening.
A 25-year-old man was arrested but later released pending further inquiries.
Anyone with information about either assault is asked to call 1800 333 000.