Cannabis is well known for causing red eyes. Several questions arise when approaching this topic. Are red eyes a sign of bad health? Should I be concerned or do something about it?

This article is meant to examine this issue from several sides, including information about the medicinal causes of cannabis induced eye reddening. Cannabis also has medicinal properties which are closely connected to the cause of eye reddening. Read along if you like. Scroll down for effective camouflage methods.

Are red eyes a sign of bad health?

Yes and No. Answers like this suck. In this case, it’s the truth.

  • Yes, from a medicinal point of view, red eyes are often a sign of health problems like flu, allergies, conjunctivitis and fatigue. Red eyes are a sign of bad health and should be examined when there hasn’t been any cannabis consumption.
  • No, red eyes are not necessarily a sign of bad health. Surprisingly, there are studies which lead to a different direction when regarding cannabis induced eye reddening.

This article will show scientific results and provide links, so you can verify the information. When assessing the medicinal benefits and risks of cannabis, it is best for individuals to form their own opinion.

red eyes causes

What are reasons for cannabis induced eye reddening?

Neuroscientists think that cannabinoids have an influence on high blood pressure, or hypertension, as well as low blood pressure, or hypotension. Scientific results, published in Neuropharmacology in 2005, formerly known as International Journal of Neuropharmacology, suggest:

“The endocannabinergic system plays an important cardiovascular regulatory role not only in pathophysiological conditions associated with excessive hypotension but also in hypertension. Thus, the pharmacological manipulation of this system may offer novel therapeutic approaches in a variety of cardiovascular disorders.”

Blood pressure and cannabis induced reddening of the eye can be very closely connected. When the blood pressure of the human body is lowered, it can lead to a dilatation of blood vessels and increased blood flow. The decrease in blood pressure can have a direct influence on the arteries of ocular globes. These arteries expand, allowing more blood to circulate through them.

If you are interested in a more detailed, scientific explanation for your red eyes you can read the chapter, Effects on the Heart and Blood Vessels, in The Science of Marijuana, by Leslie L. Iversen. See the corresponding link below.

Medicinal facts related to blood pressure, glaucoma and red eyes:

According to the World Health Organization (WHO), the global prevalence of blood pressure in adults aged 18 years and older is around 22%. This data is from 2014 and can be verified by using the link provided.

If cannabis potentially has the ability to reduce blood pressure, it will be interesting to see how the pharmaceutical industry interprets scientific results, regarding these medicinal benefits. Of course, doctors might suggest other effective treatments, like exercise, a healthy diet, stress reduction and reasonable use of alcohol. But it doesn’t seem to work for 22% of the world’s population, according to the WHO.

Scientists also found out, that cannabis can have a positive influence when used in the context of treating symptoms of glaucoma. “Glaucoma is one of the leading causes of blindness in the world”, says the article, Cannabinoids and glaucoma, published in The British Journal of Ophthalmology.

This scientific paper also states: “Cannabinoids effectively lower the intraocular pressure (IOP) and have neuroprotective actions. Thus, they could potentially be useful in the treatment of glaucoma.” If you like to dive deeper into this matter, you follow the link to the corresponding article.

What does glaucoma and low blood pressure have to do with red eyes?

At the end of the day, the lower intraocular pressure (IOP) can lead to an increased blood flow within the arteries of your eye. If more blood flows through the tiny arteries in your eyeballs, you see red, literally.

You will find a lot of scientific papers about this. It’s best to critically interpret scientific papers on your own, without being influenced by what other people think of them. Scientific results can be interpreted in many different ways.

Let’s completely focus on red eyes again.

There are several factors which can influence eye reddening:

  • Genetic predisposition: Some stoners can smoke piles of bud without getting red eyes, some take a puff and the “demon look” takes over.
  • THC Tolerance: Cannabis smokers who consume quite regularly are not very likely to have red eyes all the time. It gets better.
  • Cannabis variety: It can have a great influence what kind of cannabis strain is being consumed. The composition of cannabinoids and terpenoids varies.
  • The level of hydration: Staying hydrated is always a good thing to do. It is suspected to minimize the red-eye effect. Try for yourself if this works.

sunglasses red eyes camouflage

How to camouflage?

When being completely high in public and you are uncomfortable with your red eyes, there are several things you can do. Blending into society to make sure that other citizens don’t recognize you being high: Fun game!

  1. Sunglasses: If you don’t have sunglasses, buy a pair you feel comfortable with. Make sure that your sunglasses are not too transparent. The ones which fully reflect are ideal and probably designed for stoners.
  2.  Eye Drops: Using eye drops can be a very effective treatment. Eye drops can help eyeballs to stay lubricated and irritation free. When you need to use cannabis as a medicine and need to appear professional, for example in a business environment, eye drops are your best friend.
  3. Hydrate: Good hydration can be seen as a form of prevention method. You have to see for yourself if red eyes are related to your level of hydration.
  4. Don’t give a fuck (best advice)

Why hide for consuming a plant? This seems ridiculous in the first place. If you have to hide due to a tough legal situation in your country, you’re excused. All the other stoners can do this: Make your eyes as red as you possibly can, interact with your fellow human beings, and prove that you are the most friendly, cooperative and helpful person on planet earth.


This messes with their heads and gives them something to think about. When was the last time you confused someone? Start today!


1. Cannabis and glaucoma

2. Blood pressure regulation by endocannabinoids and their receptors (Neuropharmacology 2005)

3. WHO 22% having Problems with high blood pressure

4. The Science of Marijuana (Oxford Univertity Press)



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