- Smoking cannabis/marijuana impairs visual processing
- Marijuana is the most commonly used illegal drug in the United States, according to CDC
- Awareness campaigns are needed, as the visual deterioration can pose a danger when performing everyday tasks
Smoking cannabis is linked to alteration of key visual functions including visual acuity, contrast sensitivity, three-dimensional vision (stereopsis), the ability to focus, and glare sensitivity, said a study carried out by the University of Granada.
Yet, more than 90% of users believe that using cannabis has no effect on their vision, or only a slight effect.
A group of researchers from the Department of Optics of the University of Granada (UGR) has studied the effects of smoking cannabis on various visual parameters compared to the effect that the users themselves perceive the drug to have on their vision.
In this study, which had the approval of the Human Research Ethics Committee of the UGR (ref. 921/CCEIH/2019), an exhaustive visual trial was conducted on 31 cannabis users, both when they had not consumed any substance in advance and also when they were under the effect of the drug. The researchers also studied the participants' perception of the visual effects of having consumed this drug.
The results showed that, following consumption, visual aspects such as visual acuity, contrast sensitivity, three-dimensional vision (stereopsis), the ability to focus, and glare sensitivity significantly worsened.
Despite this, not all subjects reported a worsening of their vision after smoking cannabis. Indeed, 30% reported that their vision had not suffered at all, while 65% responded that it had worsened only slightly.
The study found a negative effect on all of the visual parameters evaluated, with the effect of cannabis on some of the parameters being analyzed for the first time in this research.
Please use one of the following formats to cite this article in your essay, paper or report:
Colleen Fleiss. (2021, April 15). Smoking Cannabis Causes Vision Impairment. Medindia. Retrieved on May 16, 2022 from https://www.medindia.net/news/healthwatch/smoking-cannabis-causes-vision-impairment-200805-1.htm.
Colleen Fleiss. "Smoking Cannabis Causes Vision Impairment". Medindia. May 16, 2022. <https://www.medindia.net/news/healthwatch/smoking-cannabis-causes-vision-impairment-200805-1.htm>.
Colleen Fleiss. "Smoking Cannabis Causes Vision Impairment". Medindia. https://www.medindia.net/news/healthwatch/smoking-cannabis-causes-vision-impairment-200805-1.htm. (accessed May 16, 2022).
Colleen Fleiss. 2021. Smoking Cannabis Causes Vision Impairment. Medindia, viewed May 16, 2022, https://www.medindia.net/news/healthwatch/smoking-cannabis-causes-vision-impairment-200805-1.htm.