Eyes are the window to the soul, the lamp to the body, and our own personal portals to the outside world – learn how cannabis can help us maintain our vision.

I’m pretty sure I don’t have to delve into the importance of vision. Just like breathing, it’s one of those background physiological functions that’s always serving us. Although we don’t actively think about the process of “seeing”, it’s something we do from the moment we open our eyes at birth. And it’s something that’s readily noticed (and particularly worrisome) when there is some sort of visionary malfunction.

Excellent vision is considered 20/20 – which refers to the size of the letter at 20 feet away from the eye chart. Surprisingly, only 35 percent of all adults have 20/20 vision without glasses, surgery, or other means of correction. Generally speaking, visual acuity develops at around six months of age and remains stable throughout the adult years. Some kids develop nearsightedness at age 8 or 9 years, and some adults experience age-related vision loss starting around age 60.

As we age, our eye’s lenses become less flexible, making it more difficult to focus on small, close objects – like words on the page of a book, for example. But aside from a touch of nearsighted vision, there are certain vision disorders that become more common as we age, two of the most common ones being glaucoma and macular degeneration.

There are some limited treatment and surgical options available, but unfortunately, many are quite invasive and can only manage the symptoms for so long. People are looking for fresh new options to deal with their vision disorders, and cannabis keeps coming up as a promising one. But is there any science to back up this claim? Let’s take a look.

Cannabis and Glaucoma

We’ll start with glaucoma, a condition that’s long been linked to cannabis.  Glaucoma is one of the most common uses for medical cannabis and was once a condition that had federal government approval for “compassionate marijuana use”.  Glaucoma is not a specific disease, per se, but rather a group of conditions that contribute to vision loss and blindness.

Research dates back all the way to the 1970s indicating that THC can reduce intraocular pressure, a key factor in the development of glaucoma. A study published in the British Journal of Ophthalmology clearly states that “Cannabinoids (specifically THC) have the potential of becoming a useful treatment for glaucoma, as they seem to have neuroprotective properties and effectively reduce intraocular pressure.”

However, that same study also points to various challenges such as unwanted cognitive effects, the development of a tolerance, difficulty in formulating a topical eye solution, and the fact that effects only last 3-4 hours, so whatever cannabis delivery method is used, it will need to be utilized 6-8 times per day.

According to Henry D. Jampel, MD, MHS, the Odd Fellows Professor of Ophthalmology at the Wilmer Eye Institute at Johns Hopkins, “The take-home message is that although marijuana can lower the eye pressure, recommending this drug in any form for the treatment of glaucoma at the present time does not make sense given its side effects and short duration of action, coupled with a lack of evidence that its use alters the course of glaucoma.”

Ok, so that’s the low-down on THC and glaucoma; but what about its non-psychoactive cousin CBD? As it turns out, that’s also not a viable option either. A 2018 study from the University of Indiana discovered that CBD increased the intraocular pressure of lab mice. Interestingly, this negative effective was twice as prevalent in male mice compared to females.

“This difference between males and females — and the fact that CBD seems to worsen eye pressure, the primary risk factor for glaucoma — are both important aspects of this study,” said Senior Research Scientist, Alex Straiker. “It’s also notable that CBD appears to actively oppose the beneficial effects of THC.”

Cannabis and Macular Degeneration

The macula is the central part of the retina and it’s responsible for focusing the central vision of the eye. As the macula deteriorates, the patient develops a blind spot in the center of their vision – although peripheral vision would remain intact. In terms of visual impact, it’s opposite of the “tunnel-vision” effect associated with glaucoma.

Many standard treatments involve injections – in the eye – that are expected to halt the growth of vascular endothelial growth factor (VEGF). But these treatments often come with various unwanted side effects, and of course, some people just aren’t too keen on sticking a needle directly into their eyes anyway (you can count me on that list).

Interestingly, researchers studying the effects of cannabinoids on brain tumors inadvertently found that they also blocked and inhibited VEGF pathways throughout the body. They found that THC was “especially effective at targeting VEGF progression”

Another theory connecting cannabis to macular degeneration is relating to the plant’s use as an anti-inflammatory, CBD in particular. Inflammation stemming from certain conditions, particularly diabetes or endotoxin exposure, is often a precursor of macular degeneration.

Keep in mind that while this all does sound very promising, these are all theories, since there have been no official studies on cannabinoid treatments and macular degeneration.

Looking Forward

If you ask any medical professional what their thoughts are on using cannabis to treat vision disorders, you will likely get a resounding “no” answer. And this is definitely not because there is no basis to the idea that it could be beneficial, but at this particular moment, the concrete evidence just isn’t there.

It’ll be exciting to see what the future holds in terms of studies and research, since new and less invasive treatment options for eye patients are in high demand. However, until there is more science, it’s best to err on the side of caution – your vision is nothing to play around with.

What are your thoughts on using cannabis to treat a vision disorder? Has it been beneficial for you? If so, we’d love to hear what you think! Drop us a line in the comment section below.