Medically Reviewed by
Jason Crawford

Article Last Updated on January 18, 2023

Getting red eyes after smoking weed is all too familiar for all the cannabis enthusiasts out there, as well as medical marijuana patients. It’s usually a telltale sign that you’ve enjoyed a doobie not long before. It’s also a cause of discomfort and stigma, especially if you live somewhere where it’s not legalized yet. Sometimes, getting bloodshot eyes is a side effect that can discourage people from enjoying it.

In this article, we’ll discuss all about eye redness due to marijuana use and give you some tips on how to reduce or prevent them. So, why does weed make your eyes red? Let’s get into it.

Who’s the Culprit?

This may not come as a surprise, but you can blame it all on THC. Here’s what happens: when THC – the main psychoactive compound in weed that gives you “the high” – enters the body, it immediately increases the heart rate, and with that, the blood pressure.

But this only lasts for about 10-15 minutes, after which the blood pressure will start returning to normal. As it lowers, the blood vessels start to dilate, causing increased blood flow. This process affects your whole body, but the eyes are a sensitive area, so it’s most noticeable there. They become red and look glossed over.

In fact, THC has the ability to reduce intraocular pressure (inner-eye pressure), the fluid pressure inside the eye, which is the key symptom of glaucoma. This is a group of eye disorders that damage the optic nerves that can eventually lead to blindness.

Therefore, even though smoking cannabis high in THC causes reddening of the eyes, it’s this effect that makes marijuana suitable for glaucoma patients.

Other Factors Involved

Besides the cannabinoids, there can be other factors that may contribute to getting red eyes from weed (that are not an allergic reaction), but these are highly individual and are by no means the rule.

  • Physiology – everyone’s bodies are different and react differently to weed, so some people may be more sensitive and prone to getting red eyes as a reaction to various things, smoking marijuana included;
  • Type of strain – each cannabis strain is unique, with its own combination of chemicals and compounds in different ratios. Each strain interacts with the body in its own way, so some strains may cause red eyes more than others;
  • Frequency of usehow frequently you use marijuana determines how tolerant you are, and your tolerance determines how susceptible you will be to red eyes. Inexperienced cannabis users will be more prone to getting weed eyes than stoners, at least the first few times;
  • Dehydration – when it comes to cannabis use, water intake is always important. When you’re dehydrated, the risk of getting red eyes is increased.

Do Edibles Make Your Eyes Red?

Many weed enthusiasts often wonder: “Do your eyes get red from edibles?” Since it’s not about the smoke from the joint getting in your eyes, but the THC content, the answer to this question will be – yes, edibles do make your eyes red. It’s especially tricky with edibles because typically, it takes longer for you to start feeling the effects, resulting in a delayed onset of bloodshot eyes.

It’s even trickier with homemade edibles because you can never be sure of the THC content, unlike those sold at dispensaries where it’s disclosed on the package. So, if your favorite edible is high in THC, you can expect to get red eyes.

How Do You Fix It?

You may have dreaded getting red eyes, but it’s definitely not a reason to give up enjoying your favorite high THC strains, even though it can be frustrating. Of course, besides being a nuisance, getting red eyes is completely harmless. Fortunately, there are some simple steps you can take to alleviate the appearance of having two red traffic lights on your head, or at least speed up the process of getting them back to normal.

Use Eye Drops

Eye drops that contain the active ingredient Tetryzoline are a great investment because this ingredient reduces the blood flow to the eyes and in this way, it causes blood vessels to shrink. If you’re a regular user of cannabis products with a high amount of THC, have these eyedrops always on hand, just be mindful that overuse could cause dryness and make your eyes redder, so just a drop or two should be enough.

Use Cold Compresses

You can also encourage vasoconstriction (shrinking of the blood vessels) by using cold compresses. You can do this in several ways. You can place slices of cold cucumber on your eyes for about 15-20 minutes. Since cucumbers have a large water content, they’ll preserve the temperature and remain cold while you wait.

You can also put used teabags in the freezer (preferable green tea, but any herbal tea is okay) and place them on your eyes in the same manner. If you’re feeling brave enough, you can also place some ice cubes wrapped in a tissue for a refreshing kick. Alternatively, splash some cold water over your face, though this will refresh you, rather than shrink your ocular capillaries.

Have Some Coffee, Cola or Chocolate

This option may sound the best because it’s the tastiest. But in all seriousness, coffee, cola, and chocolate are great vasoconstrictors because they contain caffeine, and caffeine induces shrinking of the blood vessels.

Give it Time

Finally, if you can, wait it out. Weed-eyes don’t last longer than a few hours (unless your weed was high in THC), so just try to be patient about it.

How Do You Prevent It?

Now you know what to do next time you get weed-eyes, but isn’t it better to do something beforehand to prevent it? You can try these tips to reduce the risk.

Plan Your Session Ahead

In the first place, if you want to enjoy your weed in peace without worrying about anyone noticing or feeling uncomfortable about it, make sure you clear your schedule and get comfortable. At the very least, if you have something important coming up, then give it at least a few hours for the redness to fade a bit.

Use a Low THC Cannabis Strain

Since we learned that THC is a major culprit, you can opt for a low THC and high CBD strain. This doesn’t have to be your usual choice, but on days when you want to avoid having bloodshot eyes.


Even though it’s a telltale sign you’ve been smoking, getting weed eyes is nothing to be embarrassed about, although it can be uncomfortable sometimes. The main reason behind your eyes turning red after a smoke session (or having some tasty edibles) is the THC content which causes vasodilation of the blood vessels in your eyes.

One of the ways to remedy or prevent red eyes is to choose a strain with low THC content or to use eye drops that constrict the blood vessels. In the end, the most important thing is to know that red eyes are not a big deal.

A passionate advocate for the benefits of cannabis. Fraser Horton, who has a background in botany and a strong love of nature, has spent years researching how cannabis affects the body and mind. He established Leaf Nation in 2020, where he has devoted himself to educating people about the legalisation of marijuana and its safe and responsible use. Fraser is committed to highlighting cannabis’ potential for improving wellness and working to dispel the stigma associated with its use.


The information presented on this page is provided as a public service to aid in education and is derived from sources believed to be reliable. Readers are responsible for making their own assessment of the topics discussed here. In no event shall Leaf Nation be held reliable for any injury, loss or damage that could happen if using or abusing drugs.