Army recruits exposed to CS tear gas just once during basic training had a much higher likelihood of developing respiratory illnesses such as viral illnesses like influenza, pneumonia, or bronchitis. They also don't take into account more advanced launching technologies developed in recent years that allow for the deployment of much higher amounts of tear gas over longer distances. Injuries can also occur from blunt-tipped rubber bullets. There have been cases of rubber bullets causing blindness, traumatic brain injury, and disfigurement, and less seriously, broken bones in other areas of the body. In 2020, the American Academy of Ophthalmology called on domestic law enforcement officials to end the use of rubber bullets and similar projectiles to control or disperse crowds of protesters.