Weed can be used to treat Glaucoma. Marijuana use can be used to treat the eye disease glaucoma, which increases pressure in the eyeball, damaging the optic nerve and causing loss of vision. Marijuana decreases the pressure inside the eye, according to the National Eye Institute: "Studies in the early 1970s showed that marijuana, when smoked, lowered intraocular pressure (IOP) in people with normal pressure and those with glaucoma" — though they still said that pharmaceutical drugs were more effective. These effects of the drug may slow the progression of the disease, preventing blindness. It may help reverse the carcinogenic effects of tobacco and improve lung health. There's a fair amount of evidence that marijuana does no harm to the lungs, unless you also smoke tobacco, and one study published in Journal of the American Medical Association found that marijuana not only doesn't impair lung function, it may even increase lung capacity. Researchers looking for risk factors of heart disease tested the lung function of 5,115 young adults over the course of 20 years. Tobacco smokers lost lung function over time, but pot users actually showed an increase in lung capacity. It's possible that the increased lung capacity may be due to taking a deep breaths while inhaling the drug and not from a therapeutic chemical in the drug. Those smokers only toked up a few times a month, but a more recent survey of people who smoked pot daily for up to 20 years found no evidence that smoking pot harmed their lungs. It can help control epileptic seizures. Marijuana use can prevent epileptic seizures in rats, a 2003 study showed. Robert J. DeLorenzo, of Virginia Commonwealth University, gave marijuana extract and synthetic marijuana to epileptic rats. The drugs rid the rats of the seizures for about 10 hours. Cannabinoids like the active ingredients in marijuana, tetrahydrocannabinol (also known as THC), control seizures by binding to the brain cells responsible for controlling excitability and regulating relaxation. The findings were published in the Journal of Pharmacology and Experimental Therapeutics. It also decreases the symptoms of a severe seizure disorder known as Dravet's Syndrome. Charlotte Figi has Dravet's Syndrome, and her parents are giving her marijuana to treat her seizures. During the research for his documentary "Weed," Sanjay Gupta interviewed the Figi family, who treats their 5-year-old daughter using a medical marijuana strain high in cannabidiol and low in THC. There are at least two major active chemicals in marijuana that researchers think have medicinal applications (there are up to 79 known active compounds). Those two are cannabidiol (CBD) — which seems to impact the brain mostly without a high— and tetrahydrocannabinol (THC) — which has pain relieving (and other) properties. The Figi family's daughter, Charlotte, has Dravet Syndrome, which causes seizures and severe developmental delays. According to the film, the drug has decreased her seizures from 300 a week to just one every seven days. Forty other children in the state are using the same strain of marijuana (which is high in CBD and low in THC) to treat their seizures — and it seems to be working. The doctors who recommended this treatment say that the cannabidiol in the plant interacts with the brain cells to quiet the excessive activity in the brain that causes these seizures. As Gutpa notes, a Florida hospital that specializes in the disorder, the American Academy of Pediatrics, and the Drug Enforcement agency don't endorse marijuana as a treatment for Dravet or other seizure disorders.