why do eyes turn red when smoking weed

Why Your Eyes Turn Red After Smoking Cannabis?

Thursday 23 August

The Eyes Don’t Lie – Especially When You’re High

Why cannabis causes red eyes and what to do about it

We’ve all been there, and we all know what it looks like: red eyes caused by consumption of cannabis. It’s a tell-tale sign for the practiced smoker, allowing instant recognition of fellow marijuana fans, but it is also the main giveaway for concerned parents, suspicious cops, and perceptive teachers – makes you wonder where they learned to recognise the symptoms, don’t you agree?

Since before the days of ancient Greece, the eyes have been described by poets and philosophers as ‘mirrors of the soul’. Our eyes convey a lot of information about how we feel, especially to someone who knows what to look for. This seems doubly true when we’re high: red eyes can be caused by many different things, but a good joint will certainly do the trick. In this article, we look at the causes of the phenomenon, as we try to figure out a way to work around it and perhaps hide your high from nosey onlookers…

So are red eyes harmful?

Nope, there’s no harm whatsoever in the ‘red eye’ marijuana phenomenon. We can be brief about this. Red eyes are a perfectly natural reaction of your body’s cardiovascular system to the effects of tetrahydrocannabinol (THC), which is present in just about all strains and variants of weed and hash. THC has the ability to connect with certain receptors in your nervous system, and that is how smoking a joint or eating a hash muffin affects your behaviour and biology. THC interacts with your heart and blood vessels as it does with many other parts of your body, most notably your brain. So why does your high show in your eye? Let’s expose the mechanism that is responsible for this classic stoner characteristic.


Speaking in fancy medical terms, cannabis causes red eyes through vasodilation. This is a fancy word for the widening of blood vessels and capillaries, and it is triggered by tiny muscles relaxing around the vessels themselves, allowing them to expand. This widening of the blood vessels serves to lower blood pressure, because if the heart keeps pumping blood around at the same pace, it can flow more easily through the broadened corridors of your vascular system, requiring less pressure to do so. These processes occur at the subconscious level, so we have no power over vasodilation or its opposite, which is called vasoconstriction. They are autonomous responses triggered by your nervous system, of which the so-called endocannabinoid systemis a part. As you may know or may have guessed from the name, cannabinoids present in cannabis plants can interact with this endocannabinoid system. If we get enough THC in our blood, it changes activity levels in many parts of our body. It’s just how our nerves respond to cannabis. Right after smoking a joint, people experience a brief increase in heartrate and blood pressure (through vasoconstriction), followed by a drop in heartrate and vasodilation. Now, this is when the eyes go red, because the capillaries just beneath the surface of the white in your eyeball expand. Being wider, they can contain more blood, which in this case is bright red because it carries fresh oxygen to the tissues. The tiny blood vessels in your eye will become more visible as a result, and because they are so small, anyone standing nearby will see a pinkish-red glaze where the white of your eyes used to be. Some researchers claim that more THC will cause more reddening, so you could even use your red eyes as a way to test the potency of your weed – at least in theory. So there you have it: the red is perfectly normal for smokers. Nothing unhealthy or dangerous; just a normal response beyond your control. When the high has passed, your heart rate and blood pressure return to normal, your blood vessels constrict again, and the red is gone.

Hiding Red Eyes

Since vasodilation is an autonomous process that you can’t control no matter how hard you try, it seems as if there is nothing you can do about red eyes. Fortunately, medical science has come up with a few handy tricks for any stoner aiming to keep a low profile. The first of these are chemical eye drops. They were originally developed to relieve temporary discomfort for anyone suffering from irritated eyes and allergies, but hey! Red eyes after smoking are definitely not an allergy symptom, but being super aware of your stoner look can be irritating, so this trick seems legit!

A milder solution is to use artificial teardrops, sold over the counter at any pharmacy. These are intended for people trying to get rid of dry eyes, but they soothe the tissues to such an extent that the redness will go away, even after a good smoke. Keep a bottle of this stuff handy and simply apply a few drops to your eyes. The redness will be gone in a few minutes. All you need to do now is try not to betray yourself by getting the munchies and launching an all-out assault on the fridge!

Of course, there is an easier and non-medical way to hide your red eyes, and that is a stock inventory item of any smoker: sunglasses! They’re trendy, they’re fairly inconspicuous, and they fit in any handbag. Put simply, don’t leave home without them if there is even a slight chance of smoking up ahead.

Out Of The Red

So there we go. We now know that red eyes are a perfectly natural and harmless response to THC in your system. We also know what causes it at a biological level, as well as finding a few easy ways to cover them up. Its seems as though nothing can stop us from enjoying a nice spliff without anyone noticing, so go ahead – enjoy it!

Everybody knows the fact that the eyes will turn red after smoking cannabis. Why do your eyes turn red after smoking cannabis? Read it here..


Why Does Weed Make Your Eyes Red? How to Get Rid of Stoned Eyes

Every cannabis user’s experience with the plant is unique, but there are a few telltale signs that someone has been smoking weed. There are the uncontrollable giggles, munchies, and of course, bloodshot eyes. Whether you’ve been consuming marijuana for a week or a decade, odds are you’ve looked in the mirror after a smoke session and wondered “why are my eyes red?”

The answer to that question delves deep into marijuana’s medicinal properties, the varying effects of different cannabinoids, and exactly what happens when weed enters our bodily system. And because so-called stoned eyes are a natural occurrence for both novice and experienced potheads, we’ll cover edibles, vapes, and the best options for eliminating marijuana eyes when you need to be presentable in public.

Why Does Marijuana Make Your Eyes Red?

So why does weed make your eyes red? Without getting too far into the science, it all comes down to blood pressure and blood vessels. When THC – the main psychoactive chemical in cannabis – enters the body, it causes an immediate increase in heart rate and blood pressure. The jolt to your circulatory system is akin to a jog around the block or a quick game of pick-up basketball. Unlike prolonged exercise, though, only ten minutes or so after the THC is processed, blood pressure and heart rate will return to normal resting rates.

As blood pressure begins to lower, blood vessels begin to dilate. This phenomenon happens all over the body but is most visible in the ocular capillaries. With more blood rushing to your eyes, they quickly begin to look red and glossed over. At the same time, that increased blood flow to the eyes relieves intraocular pressure. Because intraocular pressure is a key agitating symptom of glaucoma, marijuana’s quick-relief has made the plant a mainstay in the treatment of the common eye ailment since the 1990s. So while the increased blood flow to your ocular capillaries is what causes red eyes, it is also the sensation that causes relief for thousands upon thousands of glaucoma patients using medical marijuana.

How Do Different Cannabinoids Effect Eye Redness?

The eye-reddening effects of cannabis are tied directly to THC consumption. It is THC that causes increased blood pressure and heart rate, and the subsequent expansion of ocular blood vessels. In practical terms, that means that the more THC you consume, the redder your eyes will become.

As users build a tolerance to THC, though, they may notice a significant decrease in eye redness. In the same way that frequent cannabis consumption will eventually decrease the strength of intoxication, regular pot users experience less fluctuation in blood pressure and heart rate, and in turn lower levels of capillary dilation. Likewise, cannabis users who prefer CBD, CBG, or CBN-dominant strains will experience significantly less eye redness than THC consumers. Unlike the immediate rush of THC, CBD, CBG, and CBN have far less psychoactive effects, and can even decrease blood pressure, eliminating the cardiovascular reaction and eventual red eyes of traditional, full-strength THC cannabis.

Do Edibles Make Your Eyes Red?

Just like smoking flower, the eye-reddening effect of cannabis edibles depends entirely on the amount of THC in the infused product. If your favorite edible has 50mg of THC, there is a high chance that you’ll end up with bloodshot eyes. If your next magic brownie is full of CBD and only a few milligrams of THC, you likely won’t look nearly as stoned in public. Because the THC from traditional edibles is processed through the liver and not directly through the bloodstream it takes a little bit longer for edibles to get you high, and the bloodshot eye effect is similarly delayed.

The same general principle goes for vape cartridges, dabs, tinctures, topicals, and other cannabis products. If your chosen consumption method contains a fair amount of THC, the cardiovascular system chain reaction we’ve been discussing will likely cause your eyes to turn red and give away your heady habits. If you use a CBD vape cart or take a CBN tincture, you won’t let on about your cannabis secret.

How To Get Rid Of Stoned Eyes

Now that we know the science behind red eyes and which cannabis products do and don’t result in bloodshot selfies, it’s time to break down how to eliminate the pesky pot side effect. After all, cannabis is still a Schedule I drug, and sometimes it helps to hide your love affair with Mary Jane. If you need to hit a dinner party or office function after a smoke session and you don’t want to let on that you need a little weed to make the function fun, there are a few options for masking your red eyes.

First, hit up your local convenience store or pharmacy and find the eye drop aisle. Basic eye drops are a great way to quickly and easily clear the stoned look off your face. For even quicker relief, redness-reducing eye drops contain active ingredients like Tetrahydrozoline or Naphazoline that artificially clamp down the blood vessels in the eye. These products are entirely safe to use sparingly, but if used frequently, can cause eyes to dry out and could even increase eye redness if used too often.

If you’re using eye drops too often and need an all-natural cure for stoned eyes, try to up your water intake. Increased hydration won’t make your red eyes clear immediately, but it will help relieve any dryness that might keep your eyes bloodshot. Lastly, you can let your body work its course and get rid of your red eyes with the help of father time. Sure, you might need to avoid your in-laws or professors for a couple of hours, but you won’t be looking wide-eyed and paranoid into your front-facing camera, either.

Do you have a super-secret technique to cure cannabis-induced red eyes? Spill the beans and let us know in the comments below.

Every cannabis user’s experience with the plant is unique, but there are a few telltale signs that someone has been smoking weed. There are the uncontrollable giggles, munchies, and of course, bloodshot eyes. Whether you’ve been consuming marijuana for a week or a decade, odds are you’ve looked in the mirror after a smoke session and wondered ]]>