Why Does Marijuana Cause Red Eyes?

As more and more patients turn to natural, alternative treatment options, we must continue to educate both those new and familiar with medical marijuana. At Mary and Main, we believe in cannabis education in efforts to end marijuana stigma and help patients find relief. This week, we focus on how cannabis reacts with our bodies. While treating ailments and illnesses with medical marijuana, you may have noticed your eyes become bloodshot after consuming cannabis. Why does marijuana cause red eyes? People also want to know how to eliminate red eyes from smoking. There are several factors that may cause red eyes after consuming marijuana.

What Causes Red Eyes After Smoking Cannabis?

The main reason you may experience red eyes after consuming medical marijuana is due to THC lowers blood pressure, causing blood vessels and capillaries to dilate. When the capillaries in our eyes dilate, it increases the blood flow to the eyes and relieves pressure. The decrease in intraocular pressure also dilates or widens the pupils and creates a red-eye side effect. Because of this, cannabis is known to help treat glaucoma. Blood pressure decreases when cannabinoids from weed bind to the body’s receptors. 

How Long Do You Have Bloodshot Eyes from Weed?

Marijuana’s effect on the eyes varies from person to person. Everyone has a different endocannabinoid system that uniquely metabolizes cannabinoids. Some factor aside from metabolization time is tolerance level. Some heavy cannabis users may not get red eyes from weed. A high dose of THC like in dabs or edibles may give someone red eyes from smoking for hours. It all depends on the person, the product, and other factors.

Weed Bloodshot Eyes and Edibles

Weed edibles can make eyes red because they contain THC. Dab pens can also cause red eyes because they contain THC. They are very potent and can make eyes redder in some people than other products. Marijuana’s effect on the eyes varies by product and the person. Not every instance of taking edibles will lead to red eyes. Each product has a different concentration of THC. A person’s health also matters because blood pressure, genetics, and overall health are also factors. Those with high blood pressure need a higher concentration level of THC to make the blood pressure drop enough to result in eye redness.

Can CBD Cause Red Eyes

CBD can cause red eyes in some people. Experiencing red eyes as a result of consuming medical marijuana is harmless. However, if you prefer to reduce the redness, there are simple steps you can take! 

How to Get Rid of Red Eyes from Weed

Cold compress: the eye’s capillaries can get swollen after using cannabis. Decrease the blood flow by pressing a cold compress to the eyelids. Use cloth or fabric between the skin and the ice and hold it there for a few moments for relief

Eye drops: a fast way to get rid of eye redness is over-the-counter eye drops which contain tetrahydrozoline, an ingredient that constricts the eye’s blood vessels. When this happens, they don’t appear enlarged and swollen with blood. These eye drops are also used for people with allergies or difficulty from too much computer work

Sunglasses: this tried and true method has been used for a long time to cover up red eyes. They protect eyes from sun damage and add comfort to cannabis consumers who venture out in public but don’t want to answer questions about their red eyes

New Red-Eyes Support 2022

So now you know how to get rid of red eyes from smoking but what support exists today to help you along. Start by building up a tolerance. Immunity can build up to getting red eyes if used repeatedly over time. Not everyone can build a tolerance to red eyes but it is worth looking into. It is also worth looking into low-THC weed or weed without THC. High-CBD strains can be great for medical cannabis consumers and don’t come with the side effect of red eyes. Consider a conversation about whether switching from cannabis with THC to CBD is right for you. A final note is to stay hydrated. Water won’t totally erase the effects of marijuana on your eyes but it can be a great way to stay hydrated which is never a bad thing anyway.


Looking for the right cannabis products can be a challenge. Don’t hesitate to reach out to Mary and Main who offer great support and products for your journey. Even though it may be challenging to get through some of the initial side effects (like red eyes), it is worth researching products to find the best one for you and one that suits your needs. 


Mary and Main aims to help educate consumers on products and services they can access in Maryland.
Contact us to find out how we can help you select the best products for your situation.


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