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Does CBD Make Your Eyes Red?

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A small vial of CBD oil beside a hemp plant. Both of them on a wooden table.

The world of cannabis and its myriad compounds has been the subject of substantial research and discussion in recent years. Among the numerous compounds found in cannabis, cannabidiol, more commonly known as CBD, has gained significant attention for its potential therapeutic benefits for the eyes.

A question more people are asking during eye exams today is whether the consumption of CBD can lead to red eyes, a common side effect associated with cannabis use. CBD does not have the same vasodilating effects as THC, and therefore, the likelihood of CBD causing red eyes is significantly lower.

It’s also important to know that there are other contributing factors for red eyes, such as chronic conditions like dry eye disease. Learning more about the effects of CBD and the causes of red eyes can be equally important for your eyes and overall health. 

What Part of Cannabis Causes Red Eyes?

Firstly, it should be clarified that the phenomenon of red eyes after cannabis use is not a myth. The primary psychoactive compound in cannabis, delta-9-tetrahydrocannabinol (THC), is indeed known to cause ocular redness. 

Cannabis often contains both THC and CBD. CBD typically does not produce the “high” or red eyes associated with cannabis use, but it can have other effects on the body.

How Does CBD Affect the Body?

Research into CBD’s effects on the body has shown that it interacts with the endocannabinoid system (ECS), a complex cell-signalling system involved in maintaining homeostasis in the body. 

While much about the ECS remains unknown, it has been established that it plays a role in regulating a variety of functions and processes, including sleep, mood, appetite, and memory. 

CBD’s interaction with this system is thought to be responsible for its potential therapeutic effects.

How Does THC Cause Red Eyes?

The effects of cannabis on your eyes often happen due to the ability of THC to cause the expansion of blood vessels and increased blood flow throughout the body. The ocular capillaries that are in your eyes are among those that expand, leading to the reddening of the whites of your eyes.

Some studies show that THC can bind with the CB1 receptor of the endocannabinoid system in the eye, causing increased intraocular pressure (IOP). This leads to an increase in blood flow and dilation of the capillaries, thus resulting in red eyes.

In contrast, CBD has generally not been shown to affect IOP levels and therefore does not typically cause any redness or other changes to the eyes. But that does not mean that other things cannot cause red eyes when you’re using CBD.

Are There Rare Reactions to CBD?

It is worth noting that CBD is often used in the form of oils, edibles, and topical creams. However, some people may choose to get the potential benefits of CBD by smoking cannabis. 

Smoking cannabis can cause irritation and dryness in the eyes, which can contribute to redness. Therefore, the method of consumption can also play a role in whether or not CBD causes red eyes. 

Smoking cannabis may also involve consuming THC in addition to CBD, which can result in red eyes.

While it appears unlikely that CBD alone will cause red eyes, individual responses can vary. Factors such as dosage, method of consumption, and individual physiology can all influence how one’s body reacts to CBD. Therefore, it cannot be definitively stated that CBD will never cause red eyes.

Moreover, CBD products can sometimes contain trace amounts of THC, especially if they are derived from marijuana rather than hemp. Although these amounts are usually negligible, they could potentially contribute to red eyes, especially in individuals who are particularly sensitive to the effects of THC.

It should be noted that smoke generated from the act of smoking in general (regardless of cannabis, cigarettes, cigars, etc) can irritate the ocular surface of eyes, which in turn can cause redness of eyes.

What Are the Other Causes of Red Eyes?

It is also important to note that red eyes can be caused by a number of other conditions, such as:

  • Dry eye syndrome
  • Allergies
  • Excessive use of contact lenses
  • Eye strain
  • Foreign body

Therefore, you should consult an eye doctor if you experience persistent redness or discomfort in your eyes after using CBD or during other times of the day. 

Additionally, it is important to ensure that you are getting adequate rest and hydration in order to help your eyes stay healthy. With the right precautions and care, CBD can be consumed responsibly in a manner that can reduce its effects on your eyes.

Tips for Avoiding & Treating Red Eyes

A young man in a denim jacket wearing sunglasses outdoors to protect his eyes.

For those looking to enjoy the many benefits of CBD without worrying about red eyes, it is important to purchase a safely regulated product from a reputable source. 

When purchasing CBD for the benefits of CBD alone, you should make sure that it is THC-free or made from hemp with less than 0.03% THC. This amount of THC is considered low and generally does not cause any of the effects typically associated with THC consumption.

Additionally, there are some lifestyle changes that CBD users can make to support their eyes, including the following:

  • Avoid eye strain from staring at screens for long periods of time, such as computers, phones, or TVs. 
  • Wear sunglasses when outdoors in order to protect your eyes from harmful UV rays. 
  • Take regular breaks from activities that require intense visual focus, such as studying or working on a computer. 
  • Eat healthy foods and maintain a balanced diet to support your eye health.  
  • Avoid caffeine and other stimulants which may cause further stress on the eyes. 
  • Get plenty of sleep each night.
  • Avoid using any supplement or medication not recommended by your doctor.
  • Visit your eye doctor when you experience persistent eye discomfort.
  • Get regular eye exams to evaluate risks for dry eye diseases.  Many ocular issues can be prevented rather than waiting for signs and symptoms to occur. 

Following these tips can help you enjoy the potential benefits of CBD while keeping yourself safe from any potential side effects.

You Can Talk to Your Eye Doctor About CBD & Your Eyes

While THC  is known to cause red eyes, there currently isn’t enough evidence to support the idea that CBD causes the same effect. While individual responses may vary, the potential for red-eye symptoms appears to be low. 

With the right care and consideration, you can enjoy CBD without worrying about its impact on your eyes. Contact our team at Foresee Eyecare in Vaughan to learn more. We are always ready to help out by answering your questions. 

Book an appointment for an eye exam today!

Written by
Dr. Timothy H. Tsang

More Articles By
Dr. Timothy H. Tsang

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