Does CBD Make Your Eyes Red?

Scientists have known about how cannabis can affect consumers’ eyes since at least the early 1970s, when Robert Hepler and Ira Frank published their initial findings on the effects of marijuana consumption on intraocular pressure (IOP).

Hepler and Frank were focused on studying the effects of THC, which has long had a reputation for causing consumers to experience dry, red eyes. But what about cannabidiol (CBD), which has gained popularity in recent years?

In this article, we’ll explain why there is little chance that your eyes will become red or bloodshot after consuming CBD before exploring how CBD does affect the eyes, some potential treatments for red eyes, and alternative explanations for why you might experience eye redness.

Why do some cannabis products make your eyes red?

One of the earliest discoveries regarding the impact of cannabis consumption on the eyes drew a connection between tetrahydrocannabinol (THC) and IOP, though the actual mechanism through which the change in IOP occurs remains up for debate.

The impact of THC on IOP is part of a larger group of effects THC has on your blood pressure throughout the body. THC is a natural vasodilator, meaning that it causes your blood vessels to relax and expand, resulting in a drop in blood pressure. 

Multiple studies have found that THC reduces blood pressure in animal models and human studies, with the supposed mechanism being THC’s effects on the endocannabinoid system.

(It's important to note that the authors behind at least one study clarify that evidence regarding the impact of cannabis consumption on blood pressure remains too uncertain “to adopt cannabis-blood pressure policy in clinical practice.”)

You may have experienced the effects of a drop in blood pressure caused by THC if you’ve ever become lightheaded or dizzy after consuming a cannabis product containing THC.

When the blood vessels in your eyes dilate, they become visible, causing the common red eye side effect experienced by cannabis consumers. This dilation, or widening, of your ocular blood vessels also results in a decrease in IOP.

How does CBD affect your eyes?

Despite its lack of psychoactive effects, CBD does produce a variety of physical effects on the body. As readers who are well versed on the differences between CBD and THC might expect, CBD has often been reported to produce the exact opposite effects of those caused by THC.

The case of how CBD affects your eyes might follow this pattern, according to the authors of one 2018 study, CBD may actually increase IOP. However, the current findings on how common or how impactful that increase in IOP remain inconclusive, with just one of the four studies reviewed by the authors determining that CBD caused increased ocular pressure.

The findings of the 2018 study’s own experiments are similarly a mixed bag. 

The study’s authors state that exposure to CBD caused an increase in IOP for “wild-type” mice — those who share a genetic makeup commonly found in natural settings. 

In contrast, CB1 knockout mice — specifically bred to “lack all specific binding of cannabinoid agonists in the central nervous system and lose most, but not all, of the physiological responses to cannabinoids,” according to an article published in Trends in Genetics — experienced a decrease in IOP.

The authors go on to suggest that, based on this finding, CBD might be expected to increase IOP by antagonizing the endocannabinoid system’s CB1 receptors in the eyes and, at the same time, decrease IOP by antagonizing another type of cannabinoid receptor called GPR18. 

What does all this mean in practice? In the case of individuals who have found THC-rich cannabis’ ability to decrease IOP to be helpful in relieving the symptoms of glaucoma, it might be a good idea to have a conversation with your doctor before seeking out products containing high levels of CBD.

If you frequently find yourself dealing with red eyes after consuming cannabis, increasing the amount of CBD relative to THC might also offer some relief from that side effect. 

In fact, researchers have found that consuming CBD and THC together can help offset other side effects caused by THC, such as red eyes, paranoia, and greening out.

How to reduce eye redness from cannabis products

As we established above, there is little chance that consuming CBD will cause your eyes to become red. If you did experience red eyes after consuming CBD, it’s time to reevaluate who you purchase cannabis products from.

The regulation of CBD in the United States remains something of a Wild West, leaving individuals at risk of consuming a product that contains a different cannabinoid profile than what was advertised. 

In fact, in 2020 the Food and Drug Administration (FDA) released a report stating that, in a sample of 200 products ranging from tinctures to pet products, about half of those products contained some THC.

If you want to buy high quality CBD products from reliable brands, we recommend shopping for CBD using Jointly Matches. When you buy a cannabis or CBD product through Jointly Matches, you can rest assured that it comes from a pre-vetted company. 

With Jointly Matches, you’ll be able to view the certificate of analysis (COA) for your CBD products and verify based on those lab testing results whether the product has the right profile of cannabinoids and terpenes to support your wellness goals.

Jointly Matches also allows you to see how other Jointly users rated products for goals like managing aches and pains and improving sleep.

If you do experience red eyes due to THC, the main solution available to you is to use lubricating eye drops. The American Academy of Ophthalmology recommends using a brand designed to mimic your natural tears.

Other potential causes for red eyes

THC isn’t the only thing that might cause you to experience red eyes; allergies, overwearing contact lenses, infections like conjunctivitis, and a slew of other factors might be playing a role as well, according to the Mayo Clinic.

If you’re experiencing chronic red, dry, or itchy eyes, it may be time to see a medical professional who can help you trace the root cause of your condition and help you find more permanent relief. In the meantime, be aware of correlations between your cannabis consumption habits and your red eye symptoms and consider changing your habits accordingly.

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If you're ready to discover new products and reach your goals, download the Jointly app today on the App Store or Google Play, or shop your matches on the Jointly website.   

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Whether you want to improve sleep, relieve daily stress, or just relax and refresh, Jointly can help you reach your goals with cannabis.  

With Jointly, you can shop your top-rated products, and save lists of your favorites to share and bring to your local dispensary to help guide your shopping experience.  

The Jointly app also helps you improve your cannabis experiences by uncovering what’s working and what’s not with reflections and personalized insights. In fact, the quality of your diet, how much you slept, who you’re with, and the time of day are just some of the factors that can impact your cannabis experience.  

So if you're ready to find your best products and enjoy your perfect cannabis experience, download the Jointly app today on the App Store or Google Play, or shop your matches on the Jointly website. Discovery awaits.