Why do You Get Red Eyes After Consuming Cannabis?

red eyes after smoking cannabis

We’ve all been in the scenario of indulging in the aftermath of a good, old-fashioned puff, puff, pass sesh with red eyes out in full force. It’s a toker tale as old as time, but why does it happen?

The most common misconception behind red eyes after blazing up is that the smoke from your icky sticky rises and irritates your delicate little eyeballs. 

However, this isn’t actually the case.

While they may be one of the top indicators to show that you’ve taken a trip along the high scale, there’s more to this side effect than meets the eye.

See what we did there?

Jokes aside, there is legitimate science that explains why you develop bloodshot eyes after enjoying some bud. Luckily for you, that’s what we’re talking about today!

This article will expand on why cannabis causes red eyes, how to get rid of it, and whether this common side effect extends to other weed products, such as edibles.

Sit back and relax as we demonstrate our superior eye for detail regarding the causes of red eyes and potential solutions!

Why Does Weed Make Your Eyes Red?

Ingesting cannabis prompts the cannabinoids present in the plant to interact with your body’s endocannabinoid system. This relationship leads to several different side effects, including causing red eyes.

So, why does this happen? Essentially, there are two primary causes of red eyes.

The most reason is related to how THC lowers blood pressure, which causes your body’s blood vessels and capillaries to dilate.

In other words, THC causes your blood vessels and capillaries, the smallest and most numerous of the blood vessels, to expand or become enlarged.

When the THC enters your body, the capillaries in your eyes dilate, prompting an increase in blood flow. 

As the pressure in your inner eyeball lowers, the blood vessels and capillaries running through the white part of the eye have more room to expand, meaning they become much more prominent and visible.

This response is what causes your eyes to appear red or bloodshot. However, this reaction isn’t necessarily a bad thing. The increased blood flow is one reason why cannabis can treat eye conditions such as glaucoma.

Lowering the pressure in the eye can help relieve and reduce impaired vision by increasing the flow of nutrients into the nerves that transmit messages from the retina in the eye to the brain.

Marijuana can lower eye pressure, making it a potentially plausible medication for treating eye conditions such as glaucoma.

The second reason for red eyes is the misconception that we referred to earlier. 

In some instances, there is a possibility of experiencing an allergic reaction or irritation to weed smoke. In these cases, the eye redness is not unique to cannabis use, specifically, and is likely to happen with any variation of smoke exposure or irritant that comes in contact with your eyes.

The Redder Eyes the Better?

How red your eyes become ultimately depends on how much THC you consume.

Just as the more THC you ingest intensifies the other effects, such as the psychoactive properties, the more you smoke, the redder your eyes will be.

In this way, red eyes can also serve as an indicator to signify that the cannabis you’re smoking has a high cannabinoid content – aka, it’s dank weed

While it may serve as a method of busting you and giving away that you’re high, other than that, there are no real concerns about having red eyes after blazing up.

More often than not, the effect will wear off after a few hours, and you can easily rectify and treat it by having a few handy dandy tricks up your sleeve, which we’ll help you with below.

How to Get Rid of Red Eyes

As we said, the redness in your eyes from smoking weed will eventually go away on its own. However, we’ve all been in the scenario where we’ve needed to be more discreet in hiding your high! 

So, with this in mind, there are a few options at your disposal to help your eyes recover faster to avoid the awkward situation of having to awkwardly come up with an excuse on the spot like you have allergies or pink eye.

Invest in Some Eye Drops

For many, this is the easiest and most practical go-to red-eye solution. Whether you’re using artificial tears or something else, tokers have been utilizing the reliability of eye drops for red-eye relief for decades.

In other words, if you have the foresight (get it, sight?) to know that you are going to be blazing up in the near future, it would do you good to ensure that you have some eye drops in your bag or pocket for the occasion. 

All you need to do is put a drop or two in your eyes after your smoke sesh, and your enlarged blood vessels should return to normal in a matter of minutes.

Use a Cold Compress

If you’re near a fridge/freezer or just a sink with relatively cold water, creating a makeshift cold compress can provide ready relief for red eyes. Similar to how you might ice an injury, applying a cold compress could help the blood vessels in your eyes shrink back down due to the chilling temperature.

A towel soaked in cold water, an ice pack, or even a cold spoon can help relieve bloodshot eyes by easing inflammation and irritation. You can also switch out using a warm and cold compress to alleviate red eyes, using each for 5 to 10 minutes.

That said, the skin around your eyes is incredibly sensitive and susceptible to damage, so if you do opt to use a warm compress as well, be sure that it isn’t too hot.

Low-THC Strains

If you regularly find yourself falling victim to red eyes, a viable solution may be to decrease the amount of THC you’re consuming. As we said before, the more THC you consume, the redder your eyes are likely to become.

Since THC is the common denominator in this scenario, decreasing your intake should hopefully rectify the problem. 

Just because we recommend lower THC strains doesn’t necessarily mean that you won’t have as much fun as you would if you indulged in your standard sky-high strains.

There are still many captivating cannabinoids and terpenes in lower THC strains that can help contribute to the righteous entourage effect and contribute to a stellar smoking experience.

Some of our favourite low-THC strains include:


If you’re really in a pinch and don’t have access to eye drops, you’re going to have to think fast on your feet. 

As we said, there is always the option of lying and saying that you have allergies or pink eye, but another plausible, less icky solution would be to throw on some shades and hope for the best.

Ideally, this method works best if you’re outside, where it’s less odd. 

If you’re inside, you could fake having a migraine or a headache where you’re experiencing sensitivity to light.  Or, you could completely lean into it and say you’re channelling your inner Corey Hart and start singing “Sunglasses at Night!”

Wait it Out

Ultimately, if you have bloodshot eyes due to smoking up, they will eventually go away on their own. There’s no need to worry about any negative or adverse outcomes other than potentially being judged by your parents, peers or nosy neighbours.

Really, all that causes bloodshot eyes is an increase in blood flow after consuming THC. There is also evidence that states that ingesting caffeine, dark chocolate, licorice, and sodium can also constrict the blood vessels in your body, reducing the redness.

So, if you’re hit by a wave of the munchies and want to get rid of your red eyes, you can get two birds stoned at once if you catch our drift!

Do Edibles Cause Bloodshot Eyes, Too?

While many people believe that bloodshot eyes are the direct result of smoking, this is a common misconception. 

No matter what type of consumption method you use, be it smoking, dabbing, vaping, or ingesting edibles, your eyes will likely become red.

As we’ve touched on already, it’s not the act of smoking itself that makes your eyes red, although smoke may cause irritation, eye pain and trigger allergies in some users. 

The primary cannabis culprit behind your red eyes is the THC itself, which is present in all of these various vessels.

It’s the tetrahydrocannabinol (THC) that causes the temporary decrease in blood pressure throughout all the veins, capillaries and arteries throughout the entire body, including your eyes. 

So, if you were hoping for a solution to avoid red eyes while still indulging in your THC fix, we’re sorry to disappoint! 

However, ingesting lower-THC strains may help ease the blow a bit. Additionally, CBD strains will not cause this red-eye effect.

Red Eyes – It’s Only Temporary

Red eyes are a key signifier to determine if someone has been indulging in some icky sticky. That said, if you’re super worried about drawing attention to yourself and your weed use, there are several ways to help tone them down and treat bloodshot eyes, including using a cold compress or having eye drops handy.

You can also take comfort in knowing that this side effect is incredibly common and will eventually go away on its own. 

If you notice that your red eyes do not go away and are experiencing dry eye, blurry vision or other vision changes, it may not be because of cannabis use. It could instead be due to a different condition.

In these cases, it’s best to see a doctor for some medical advice.

If you’re a frequent smoker, testing out some lower THC strains may also be a plausible solution for avoiding red eyes. 

Visit the Buy Low Green website to peruse our extensive flower selection. We do not doubt that you’ll find something to suit your weed needs.

Happy toking!

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