Does Marijuana Use Affect a Person's Vision?

Regular marijuana use may affect how well certain cells in the eye's retina function, a small new study finds. The cells that the researchers focused on in the study, called retinal ganglion cells, are located near the inner surface of the eye's retina. The study included 52 people who had used marijuana at least 7 times per week during the previous month and 24 people who had never used marijuana.