The American Academy of Ophthalmology recently published an article on a popular topic that tends to be filled with a lot of ambiguity. The article suggests while there are two varying opinions on impacts of marijuana and night vision, there is not enough data on the long-term residual effects. On the front of marijuana being helpful for glaucoma, while there has been an established connection of marijuana lowering pressure, the effect is so short-lived that one would need to smoke every hour or two hours around the clock to achieve the same control of glaucoma drops.
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Feb. 28, 2017
Are marijuana鈥檚 effects on vision good or bad? Two new studies suggest there isn鈥檛 one easy answer, and neither one considers long-term impacts.
One study of tadpoles suggests marijuana may enhance night vision, while a human study indicates that regular cannabis use may delay the processing of visual information in the retina.
The聽first study聽explains a cellular mechanism by which marijuana may improve night vision. The research is based on an observation that Jamaican fisherman who smoked or consumed marijuana had excellent night vision. In the new study, researchers at McGill University in Montreal applied a synthetic cannabinoid to the eye tissues of tadpoles. They found the cannabinoids made certain retinal cells more sensitive to light, and improved the speed and which the eye responded to even dim stimulus, The Guardian reports. Cannabinoids are the general class of chemicals that聽. The body naturally produces some cannabinoids. Other cannabinoids come from marijuana or other sources.
The included 28 marijuana users and 24 people who did not use the drug. The researchers compared the working of the retina in both groups to see whether marijuana affects the function of cells called retinal ganglion cells. These cells are responsible for transmitting electrical pulses from the eye into the brain, CNN reports.
The study found there was a delayed response time for marijuana users compared with people who did not use the drug. This may impact the eyesight of people who use marijuana regularly, even if the influence is very weak, the researchers said.
鈥淭hese studies both have interesting findings, but neither answers the question of whether marijuana affects vision over the long term,鈥 says Raj Maturi, MD, associate professor of ophthalmology at Indiana University School of Medicine. 鈥淢arijuana might help some aspects of vision in the short term, but it might be harmful if used chronically. These findings suggest we need longer-term studies of the effects of chronic marijuana use on vision.鈥
Dr. Maturi notes that patients with often say they have heard that marijuana may be helpful by lowering pressure in the eye. He tells them marijuana may be able to decrease the pressure a little bit, but at the same time the drug is acting on the brain and nervous system in ways that may be harmful.
鈥淢y view is that eyedrops that decrease the pressure in the eye are far more useful. You would have to smoke quite a lot of marijuana to get the same effect,鈥 Dr. Maturi says.
Some studies on have found that when marijuana is smoked or when a form of its active ingredient is taken as a pill or by injection, it does lower pressure in the eye, or intraocular pressure. However, it only lowers the pressure for a short period of time鈥攁bout three or four hours.
The American Academy of Ophthalmology as a treatment for glaucoma.
A by the National Academy of Sciences on the health effects of marijuana concludes that studies suggesting positive effects of marijuana on glaucoma 鈥渉ave shown only short-term benefit on intraocular pressure (hours) suggesting a limited potential for cannabinoids in the treatment of glaucoma.鈥
Speak with your to find the glaucoma treatment option that is best for you.
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