Marijuana Side Effects: Regular Cannabis Use May Affect Vision
A new study published in the journal JAMA Opthamol has found that regular marijuana use can cause a delay in visual processing.
CNN reports that using marijuana regularly may affect a person's vision. This is due to a slight delay in the retinal ganglion cells (RCGs), which are responsible for processing visual information from the retina to the brain.
For the study, the researchers compared the visual processing of 28 regular marijuana users -- who smoke weed at least seven times a week -- to 24 people who never used cannabis. They found out that regular marijuana users have a 10-millisecond delay in their visual processes where their RCG's send signals through their optic nerve to the brain.
The research team warned that pot users may be experiencing vision problems without actually being aware of it. However, researchers admit that their study was small. Furthermore, they cannot yet conclude if the said delay would be permanent or if the visual processing will be back to its normal speed when the user stops using marijuana.
"Such an anomaly could be imperceptible for cannabis users," said study's lead author, Dr. Vincent Laprevote, physician at Pole Hospitalo-Universitaire de Psychiatrie du Grand Nancy in Laxou, France. "However, it is important, since it could reflect the changes in the communication between neural cells implied by regular cannabis use."
Laprevote added that they focused on ganglion cells since they also work like brain cells. Previous studies suggested that regular marijuana use could indeed affect brain processing.
In fact, another study shows that smoking pot lowers blood flow in the brain's right hippocampus, which is responsible for memory functions.
According to the study's co-author Dr. Elisabeth Jorandby, "marijuana use has damaging influences in the brain - particularly regions important in memory and learning and known to be affected by Alzheimer's." Despite its medicinal benefits, marijuana users should at least be warned of its harmful effects before it is too late.