Red eyes : How does cannabis affect vision?

The big debate…

This is a less contentious issue than maybe a few years ago but still one debated the world over, cannabis use and the legality thereof is something governments are starting to accept as the inevitable forward march of progress, rather than another failed prohibition.

We’re not campaigners, stoners nor prohibitionists, but we are eyewear enthusiasts and eyecare fanatics so we thought we’d try to have a look at the evidence and give you what we think is an objective view of the latest thinking on eyes and weed.

Perhaps the most well known benefit of cannabis products for the eyes is its use in the treatment of glaucoma. Glaucoma, for those that don’t know, is a condition causing damage to the optic nerve by the pressure of the fluid inside the eye. This has very few symptoms at first, and if left untreated, can eventually cause sight loss.

Thanks to the THC in cannabis, there is a reduction in blood pressure when smoking weed, resulting in the relaxation and dilation of your blood vessels reducing the pressure inside the eye. Unfortunately these benefits whilst well documented, seem to be very temporary, lasting only a few hours and we have yet to find a way of obtaining them without the usual side effects.

“One of the most noticeable effects occurs shortly after smoking the drug: red eyes. THC (tetrahydrocannabinol) in marijuana lowers blood pressure which dilates the blood vessels and increases blood flow throughout the body. This causes the blood vessels in the eyes to expand, causing redness or bloodshot eyes.” – The Canadian Association of Optometrists

Evidence published in 2014 also suggested that cannabis compounds may slow the progress of degenerative blindness in conditions such as retinitis pigmentosa. The study (on rats) seemed to show the cannabis preventing the deterioration and death of the photoreceptors in those with the condition. Rats treated with the cannabinoid had up to 40% more photoreceptors at the end of the study.

On top of these benefits, a bit of marijuana can also help your night vision by making certain cells respond better to low light stimulus. This benefit does seem a little limited though, as anyone needing to function well at night would certainly do better not operating totally stoned.

It appears for now there are certain benefits to cannabis and cannabis compounds for a whole range of health issues, including but not limited to eyes however we have yet to harness the true benefits of this interesting plant without the undesired (in some cases) side effects. It also goes without saying that anything involving tobacco use does more harm than good, but with big business and governments around the world taking a serious look at the possible medical applications, big developments are on the horizon. Canada has just legalised!

P.S. Just in case you’re a few grams short of an eighth, this article does not constitute medical advice and should not be used in place of a doctor should you have any concerns about the eye conditions mentioned here or anything else. Regular eye tests are essential for continued good vision and also monitor the health of your eyes.

Head to http://www.insightopticians.co.uk/ to book an eye test today!