My Journey with Glaucoma and Cannabis
My connection to glaucoma isn’t just academic — it’s personal. Years ago, I was sentenced in the United States to 121 months — ten years and one month — for cannabis-related offenses, moving flower from Canada into the States during prohibition. Under the U.S. federal system, you serve 85% of your time, and that’s exactly what I did: eight and a half years behind the wall.
While I was inside, I was diagnosed with glaucoma. The standard treatment was prescription eye drops, and I was on them for seven of those years. They cycled me through medications like brimonidine and latanoprost — one of which came with the warning that it could even change my eye color from blue to brown. Every day was drops, bottles, and routine, and that became my reality.
When I returned to Canada, I kept up with the drops, but I also started using cannabis again. It was part of my life before prison, and once I was back in the free world, it became part of my routine again. Not long after, I had to take a full eye exam for my Class 1 truck driver’s license. I’ll never forget the surprise when the doctor told me: I wasn’t showing signs of glaucoma anymore. At that point, I’d actually been off my drops for a short while — no prescription, no daily bottles.
Now, I’m not claiming cannabis cured my glaucoma — that’s not the message. But that moment made me stop and ask myself: could cannabis have been playing a role? After years of being told my only option was drops with side effects, the possibility that cannabis had a part in protecting my eyes lit a fire under me. It pushed me to dig deeper into the research and start connecting the dots between what the science shows and what real people experience.
Cannabis and Glaucoma: Current Research Overview
The big picture hasn’t changed: THC can lower intraocular pressure (IOP), the main risk factor in glaucoma. Modern controlled work shows about a ~16% IOP drop after inhaled THC, but the effect is short—hours, not all day—which is the core limitation for a 24/7 disease like glaucoma.
https://www.frontiersin.org/journals/medicine/articles/10.3389/fmed.2021.736792/full
Delivery is the second hurdle. Systemic THC reliably affects pressure, but most topical/ocular formulations haven’t shown consistent, sustained IOP reduction in humans. In short: the biology is real, but practical eye-specific delivery isn’t there yet for everyday care.
https://pmc.ncbi.nlm.nih.gov/articles/PMC11521503/
CBD is not a substitute for THC here; in fact, at certain doses CBD may raise IOP and can antagonize CB1 signaling, which is part of how THC lowers pressure. That’s why “CBD for glaucoma” isn’t a safe assumption.
https://pmc.ncbi.nlm.nih.gov/articles/PMC6295937/
Because of the short duration and delivery/side-effect issues, professional bodies do not recommend cannabis as primary glaucoma therapy. First-line options remain prescription drops, laser, and surgery as needed.
https://www.aao.org/eye-health/tips-prevention/medical-marijuana-glaucoma-treament
Researchers are still exploring benefits beyond pressure—for example, a randomized trial found low-dose oral dronabinol increased optic nerve head blood flow in healthy subjects (signal, not practice-changing). It’s an area to watch, but still early.
How THC Affects Intraocular Pressure
Here’s the “how.” The endocannabinoid system is active in ocular tissues. THC engages CB1 receptors in the ciliary body and elsewhere, which can reduce aqueous humor production and support outflow—together lowering IOP.
https://pmc.ncbi.nlm.nih.gov/articles/PMC11521503/
Onset and duration: with inhaled THC, the IOP-lowering effect shows up quickly and peaks within a few hours, then fades. That’s why multiple daily doses would be required to sustain pressure control—impractical for most people.
https://www.frontiersin.org/journals/medicine/articles/10.3389/fmed.2021.736792/full
There’s also interest in neuroprotection/vascular effects beyond pressure (e.g., retinal cells, optic nerve blood flow). Preclinical and early human work suggests potential, but clinical proof for long-term vision protection isn’t established.
https://pmc.ncbi.nlm.nih.gov/articles/PMC10460067/
Formulation reality: oral THC can last longer but is variable in onset/potency; most eye-drop attempts haven’t penetrated tissues well enough to matter. Until ocular delivery improves, THC’s mechanism remains more of a scientific lead than a day-to-day glaucoma treatment.
Cannabis vs. Traditional Glaucoma Treatments
Glaucoma care is about 24/7 pressure control to protect the optic nerve over years. First-line treatments are well-established: prescription eye drops, laser procedures, and surgery as needed — all designed for sustained IOP reduction across the day and night.
https://www.aao.org/eye-health/diseases/what-is-glaucoma
Among drops, prostaglandin analogs are typically the starting point because they’re effective, once-daily, and generally well tolerated, with other classes (beta-blockers, carbonic anhydrase inhibitors, alpha-agonists) added or substituted as needed.
https://www.ncbi.nlm.nih.gov/books/NBK562924/
Selective laser trabeculoplasty (SLT) is supported by high-level evidence as an effective long-term option and, in some cases, can be used early instead of drops; it improves aqueous outflow from the eye to lower IOP.
https://www.aaojournal.org/article/S0161-6420%2823%2900561-4/fulltext
When drops and laser aren’t enough, surgeons may recommend MIGS (minimally invasive glaucoma surgery), trabeculectomy, or drainage devices to achieve round-the-clock pressure control and slow disease progression.
https://www.mayoclinic.org/diseases-conditions/glaucoma/diagnosis-treatment/drc-20372846
Where does cannabis fit against these standards? Modern controlled work shows inhaled THC can lower IOP — on the order of ~7–16% — but the effect lasts about four hours, not the full day glaucoma management requires. Multiple daily doses at levels that cause psychoactive effects make it impractical as a primary therapy.
https://www.frontiersin.org/journals/medicine/articles/10.3389/fmed.2021.736792/full
CBD is not a substitute here; in a pilot with glaucoma patients, sublingual 20 mg CBD did not reduce IOP and 40 mg CBD increased IOP, whereas 5 mg Δ9-THC lowered it temporarily.
https://pubmed.ncbi.nlm.nih.gov/16988594/
The main R&D barrier is ocular delivery: getting cannabinoids into the right eye tissues at therapeutic levels for long enough without systemic side effects. Reviews note that while systemic THC shows effects, topical formulations have struggled to deliver consistent, sustained IOP reduction in humans.
https://www.ncbi.nlm.nih.gov/books/NBK572112/
Cannabis may have a role as an adjunct/experimental option discussed with an ophthalmologist, but it does not replace proven first-line treatments aimed at continuous pressure control and long-term vision preservation.
Making Sense of the Research: What It Means for Real Life
Alright, let’s step back for a minute. We’ve just gone through a lot of science and clinical detail, but what does it all really mean if you’re just trying to understand cannabis and glaucoma in everyday terms?
The first thing to know is this: cannabis can lower eye pressure. That’s been shown many times, mostly with THC. The catch is, the effect doesn’t last long. We’re talking hours, not days. Glaucoma is a 24/7 condition, which means you need something that keeps eye pressure down around the clock. That’s why doctors lean on prescription drops, laser treatments, or surgery — because those give you steady control, not just temporary dips.
Second, a lot of people assume CBD works the same way as THC, but it doesn’t. In fact, in some studies CBD actually raised eye pressure instead of lowering it. So if you’ve heard people say “CBD is good for glaucoma,” that’s not backed up by the evidence.
Third, the way cannabis is used makes a difference. Smoking or vaping THC can lower eye pressure quickly, but it wears off just as quickly. Taking THC by mouth can last longer, but it’s unpredictable and brings along side effects that most people wouldn’t want to deal with every few hours, every single day. Eye-drop versions of cannabis have been tested, but so far they haven’t worked the way doctors hoped.
So, where does that leave us? Right now, cannabis is not a replacement for standard glaucoma treatment. If you have glaucoma, you need to be under the care of an eye doctor and follow their guidance. But — and this is the important “but” — cannabis does seem to affect the same systems in the eye that glaucoma treatments target. That means there’s potential for the future, if researchers can figure out better delivery systems and maybe even new ways of protecting the optic nerve.
In plain language: cannabis shows promise, but it’s not the miracle answer for glaucoma today. Think of it as a piece of the puzzle — something that might help for a short time, or something researchers might one day develop into a new kind of therapy. For now, though, it’s best seen as a side conversation with your doctor, not as a stand-alone solution.
Safety Considerations for Cannabis and Glaucoma
If you’re thinking about cannabis as part of glaucoma care, the first thing to know is that it’s not considered a main treatment. Glaucoma needs steady, round-the-clock pressure control, and cannabis just doesn’t last that long. Drops, laser, and surgery are still the backbone of treatment, and cannabis should only ever be seen as a possible add-on, not a replacement.
The short duration is one of the biggest challenges. Even when THC lowers eye pressure, it only does so for a few hours at best. To keep pressure down all day, you’d have to use cannabis several times, and at doses that come with side effects like feeling high, slowed reaction time, and sometimes dizziness. That’s not realistic for most people.
There are also everyday safety concerns. Cannabis can affect focus, coordination, and reaction time, so driving or operating machinery after use is a risk. Older adults may also find cannabis increases their chances of losing balance or feeling unsteady. It’s important to be cautious, especially if you’re new to cannabis or already dealing with other health conditions.
Not all cannabis is the same. THC is what lowers eye pressure temporarily, but CBD doesn’t work the same way. In fact, CBD has sometimes been shown to do the opposite — raising eye pressure instead of lowering it. That’s why products labeled as “CBD for glaucoma” should be approached with caution.
Finally, cannabis can interact with other medications. If you’re already using prescription eye drops or taking other drugs for blood pressure, heart issues, or any long-term health condition, it’s smart to check in with your doctor or pharmacist before adding cannabis to the mix.
In short, cannabis can play a role in the glaucoma conversation, but it comes with limits and risks. If you’re curious about exploring it, do so carefully, keep your doctor in the loop, and always prioritize treatments that are proven to protect your vision for the long haul.
Patient Experiences with Medical Marijuana for Glaucoma
Glaucoma was one of the earliest reasons people reached out to me about cannabis. Long before legalization, folks were experimenting because they’d heard “it lowers eye pressure.” What I’ve heard over the years is mixed, and that honesty matters here.
On the positive side, some people report that a small amount of THC helps them feel less “pressurey”—that vague, behind-the-eye tension—especially in the evening. A few noticed cleaner sleep and calmer nerves around appointments. Others found cannabis useful for the life around glaucoma: easing stress, helping with the anxiety of progressing disease, or replacing an after-dinner drink so they wake clearer for morning checkups. The wins, when they happen, tend to be practical: better wind-down, less worry, a little more comfort.
On the challenging side, real-world use runs into real-world limits. The eye-pressure effect doesn’t last; you’re talking hours, not the whole day. That means frequent redosing if you’re chasing pressure alone—and at doses that some people find too psychoactive to function. A few older adults told me they felt unsteady or light-headed when they tried to time cannabis around evening routines. Others found that products labeled as “CBD” didn’t match their expectation for eye pressure at all. More than once, someone felt they were “doing something” for their glaucoma with CBD, only to learn at their next appointment that their pressures weren’t where they needed to be.
Where people seem most satisfied is when they treat cannabis as adjunct support, not a replacement for drops, laser, or surgery. That looks like: keeping the regular treatment plan, using a low dose of THC after dinner to take the edge off, and pairing it with a healthy ritual—stretching, a warm shower, a short walk—so bedtime arrives more gently. It also looks like being honest about safety: no driving after use, first tries at home and seated, and a plan to stop if anything feels off.
Think in terms of a simple experiment rather than a promise. Pick one clear goal (stress relief, easier sleep), choose a low-dose product, try it on a quiet evening, and keep notes for your next appointment. Bring your log to your eye doctor and make decisions together. That’s the bridge I’m trying to build here: respect for the evidence, respect for lived experience, and respect for your vision over the long haul.
FAQs: Cannabis and Glaucoma
Does cannabis really help glaucoma?
Yes, but only in a limited way. THC can lower eye pressure, which is the main risk factor in glaucoma, but the effect only lasts a few hours. That’s not enough to replace drops, laser, or surgery, which provide round-the-clock pressure control.
Can CBD help with glaucoma?
Not in the way most people hope. Unlike THC, CBD doesn’t reliably lower eye pressure. In some cases, it may even raise it or interfere with THC’s effect. CBD can still play a role for relaxation, stress, or sleep, but it isn’t considered a glaucoma treatment.
Why don’t doctors recommend cannabis for glaucoma?
Because glaucoma is a 24/7 disease, and cannabis only lowers pressure for short periods. To use cannabis as your only treatment, you’d need to dose multiple times a day at levels that cause side effects, which isn’t practical or safe.
Can cannabis replace my prescription eye drops?
No. Cannabis should never replace proven treatments prescribed by your ophthalmologist. If you’re curious about adding cannabis for comfort or stress relief, talk to your doctor first and use it only as an adjunct, not as a substitute.
What about edibles or tinctures — do they last longer?
Oral THC can last longer in the body, but it’s harder to predict onset and effect. Some people find the longer duration helpful, but it still doesn’t match the steady, controlled effect needed for glaucoma management.
Is cannabis safe for older adults with glaucoma?
Older adults can be more sensitive to cannabis side effects like dizziness, balance problems, or confusion. That means the risk of falls or accidents is higher. If you’re older and curious about cannabis, start with very low doses, in a safe environment, and always let your doctor know.
What’s the safest way to try cannabis if I have glaucoma?
Think of it as an experiment, not a cure. Start with a low dose of THC (or a balanced product), try it in the evening at home, log how you feel, and bring that information to your next eye appointment. Always keep your prescribed treatment plan in place.
A Final Word from Doktor High
Glaucoma isn’t just a topic I researched — it’s part of my story. I spent years on prescription eye drops, worried about side effects and wondering if there was anything else I could do. After serving 121 months in the U.S. for cannabis-related offences — and completing the 85% required under the federal system — I came home to Canada, stayed on my drops, and cautiously brought cannabis back into my life. A later eye exam surprised me: I wasn’t showing signs of glaucoma at that time. I’m not claiming a cure, and I didn’t toss my prescriptions in the bin. What I took from that moment was a question — and that question sent me deep into the evidence and into thousands of conversations with people walking the same path.
Here’s where I’ve landed: cannabis can play a role, but it’s a tool, not a replacement for proven glaucoma care. THC can lower eye pressure for a few hours; that’s real. It’s also limited. Glaucoma is a 24/7 condition, and protecting vision is a marathon. For most people, that means drops, laser, or surgery — and if you’re curious about cannabis, you treat it as adjunct support, not a standalone plan.
What cannabis can add, when used thoughtfully, is quality of life: calmer evenings, better sleep, a softer edge around the stress of appointments. Used with intention — low dose, smart timing, honest journaling — it can help some people feel more themselves while they follow the plan that safeguards their sight.
If my experience has any value to you, it’s this: stay curious and stay grounded. Ask your eye doctor questions. Bring data from your own life. Keep what works, let go of what doesn’t, and never gamble with your vision. That’s the bridge I try to build on every page here — between science and street, between what the studies show and how we actually live.
With respect for your eyes and your journey,
— Doktor High 🌿
