This is a really popular question I get as an eye doctor. Although marijuana can lower eye pressure, it isn’t really recommended due to the side effects, short duration of action, and lack of evidence.
Worldwide Blindness
After cataracts, glaucoma is a leading cause of blindness worldwide, affecting more than 60 million people. Glaucoma is a disease where the optic nerve is damaged. The optic nerve carries visual signals from the eye to the brain. Damage to this part of the eye causes vision loss and eventually blindness. Usually, the damage to the optic nerve is caused by high eye pressure. Treatment for this is either eye drops or surgeries to lower the eye pressure and prevent further damage and vision loss.
Does Marijuana Lower Eye Pressure
So, is marijuana a good option for lowering eye pressure? Not really. Smoking marijuana will lower eye pressure, but it only lasts for 3-4 hours. So, in order to lower the eye pressure throughout the whole day it would have to be smoked 6-8 times a day. Other medicines reduce eye pressure equally well and need only be taken once or twice a day. Marijuana prevents patients from driving and functioning at full mental capacity so smoking all day would really not be an option for most people. Marijuana cigarettes also contain compounds that damage the lungs and chronic use can cause brain damage. Consider this: Alcohol also lowers eye pressure for an hour or so after a drink. But no doctor would recommend that you drink alcohol every hour to treat glaucoma. Many other effective treatments are available that don’t have the side-effects of alcohol.
There are ways to ingest THC, the active ingredient of marijuana, that avoid the harmful effects of marijuana smoke, but there are still systemic side effects such as drowsiness and loss of judgement. There is some evidence that a synthetic cannabinoidlike compound known as HU-211 has nerve-protecting properties. However, it does not reduce eye pressure. HU-211 is chemically similar to THC, but it is not found in the marijuana plant and does not bind to the cellular receptor in brain cells that THC activates.
Don’t Forget About Blood
Marijuana does lower eye pressure and blood pressure as well. Lower blood pressure can cause the blood supply to the optic nerve to be reduced. This can harm the optic nerve. This is the opposite effect that you want! For this reason and many others, marijuana is not recommended without a long-term clinical trial for glaucoma.