Ask Cheri

Why Does Weed Make Your Eyes Red and How Can You Reduce Red Eyes? 

By Cheri Sicard
February 29, 2020

Dear Cheri,

Am I going crazy?   My eyes always get red after smoking marijuana, but other day I did not smoke at all although I did eat a marijuana brownie.  Do edibles make your eyes red?  My eyes were red the same way they are after smoking.  What’s going on? I always assumed it was irritation from smoke that made your eyes red.  So my question is why does weed make your eyes red and do edibles make your eyes red too?  OK, that’s two questions.   Thanks in advance for your insight and all your great educational content, I have learned so much from you already.

Awww, thank you for your kind words.  OK, quick answer, no you are not going crazy…at least not because of asking if edibles make your eyes red.

To be sure different people have different sensitivities to the red eye phenomenon, but first and foremost having red eyes after using marijuana is not dangerous and might even be beneficial.

Believe it or not, how much your eyes turn red can have a lot to do with the amount and quality of the herb you are consuming, regardless of how you consume it.

That’s right it does not matter if you smoke cannabis, vape it, or eat infused edibles, these ingestion methods can ALL result in red eyes.

That’s because it is not the smoke in marijuana that causes redness but rather the THC.  So you were not imagining your red eyes after consuming a pot brownie.

Why Does Weed Make Your Eyes Red: The Science Behind the Phenomenon

The reason THC turns your eyes red is the same reason cannabis can be effective as a glaucoma treatment, namely it lowers intraocular pressure.

This happens because THC reduces blood pressure and dilates capillaries.  When ocular capillaries dilate that increases blood flow to the eyes and creates redness.

Likewise, a strain that has a higher THC content is likely to make your eyes redder than one with low THC.

How to Reduce Red Eyes from Cannabis

Even though red eyes after using cannabis is not harmful, there are definitely occasions when you might not want to to be broadcasting this telltale clue that you’ve just had an encounter with “Mary Jane.”

So is there anything you can do to reduce red eyes? 


  • Eye drops, especially those formulated to reduce red eyes can definitely help, especially if you need fast relief. Check out Amazon’s BEST-RATED eye drops for redness here.
  • As we have already discussed, less THC means less redness so you should likewise save your potent top shelf for later if you are trying to avoid red eyes. In fact, this is a good time to break out the CBD.
  • It’s questionable at best whether drinking water actually helps with eye redness, despite this frequently repeated advice. That said drinking water is good for you, most people don’t get enough, it can fight eye dryness (a secondary cause of redness), and it also counteracts marijuana’s other annoying side-effect, cotton mouth.  So I say drink up!

red eyes and marijuana smoke

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About the author

Cheri Sicard is the author of Mary Jane: The Complete Marijuana Handbook for Women, and The Easy Cannabis Cookbook.  Her online courses at have educated 1000s of students about marijuana, cannabis cooking for home cooks, and making infused topicals.

  • Hi Cheri.. complete novice.. contacted you on YouTube.. once I’ve decarbed.. in the FX.. to make potent firecrackers.. do I need to heat again in the FX? Cheers

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