The London-based NGO Amnesty International called for better global regulation of the trade and use of rubber bullets and such policing equipment, also called "less lethal weapons", after research in more than 30 countries over the past five years.
These included rubber bullets, rubberised buckshot, and tear gas grenades fired directly at demonstrators in south and central America, Europe, the Middle East, Africa, and the United States.
"Thousands of protesters and bystanders have been maimed and dozens killed by the often reckless and disproportionate use of less lethal law enforcement weaponry," it said in a new report titled "My Eye Exploded".
"There has been an alarming increase in eye injuries, including eyeball ruptures, retinal detachments and the complete loss of sight," Amnesty said.
In Chile alone, the police's response to protests from October 2019 caused more than 30 cases of eye loss, according to the country's National Institute for Human Rights.
Other demonstrators in countries surveyed had also suffered bone and skull fractures, brain injuries, the rupture of internal organs, or punctured hearts and lungs from broken ribs, it added.
Demonstrators have also been killed, the report co-written with the UK-based Omega Research Foundation found.
In Iraq, security forces deliberately fired specialist grenades that are 10 times heavier than typical tear gas munitions at protesters, causing at least two dozen deaths in 2019, Amnesty said.
In Spain, the use of tennis-ball-sized rubber projectiles has led to at least one death from head trauma, according to campaign group Stop Balas de Goma.
"Legally-binding global controls on the manufacture and trade in less lethal weapons... along with effective guidelines on the use of force are urgently needed to combat an escalating cycle of abuses," said Amnesty International's Patrick Wilcken.