Believe it or not, the idea that cannabis might enhance night vision is not a very recent one. One report on the matter was published about 25 years ago and another has been out for more than a decade.
The first study that was done was published by the pharmacologist M. E. West of the University of the West Indies in Kingston, Jamaica. In the study, West wrote about how local fisherman seemed to have “an uncanny ability to see in the dark”, resulting in what he thought to be superior boat navigation skills through the coral reefs. What the majority of these fishermen had in common was that they consumed some form of cannabis – either by smoking it or drinking rum that contained leaves and stems.
“It was impossible to believe that anyone could navigate a boat without a compass and without light in such treacherous surroundings,” West said, after observing a fishing crew at work one night. He said he was convinced that the cannabis resulted in far better night vision than he had, and that a “subjective effect was not responsible.”
West’s study, and others like it, indicated that more CB1 protein receptors are located in the eye than in the brain for cannabinoids to bind to. As interesting as these studies were, and still are, they offer little else to explain the physiology of the effect cannabis may have on night vision.
The desire to better understand the impact cannabis may have on night vision is what drove researchers from the Montreal Neurological Institute in Canada to recently publish a study in the journal of eLife. The research team tested a synthetic form of a cannabinoid on the eye tissues of African clawed toad tadpoles, using microelectrodes to measure how the tadpoles’ eye cells responded to light.
The eye cells of the tadpoles responded more rapidly to bright and dim light. In addition to the cannabinoids binding with the CB1 receptors, the researchers wrote that a protein called NKCC1 was inhibited. This protein reportedly brought chloride ions in and out of the eye cells, improving electrical potential.
“Overall, these experiments show that cannabinoids reduce the concentration of chloride ions inside the retinal ganglion cells, making them more excitable and more sensitive to light,” The Guardian reported.
It would obviously be of interest to test a natural form of cannabis on humans to see if improved night vision after ingestion is a real thing. Of course, cannabis prohibition prevents most of the further study needed on the plant medicine. This interesting story is yet another example of how those antiquated laws are holding us back from fully discovering the vast array of potential benefits of cannabis.