How Does CBD Affect the Eyes & Overall Eye Health

Cannabidiol (CBD) is derived from the hemp plant. It is a legal, non-intoxicating ingredient found in cannabis. The drug’s popularity keeps growing more and more in the U.S. 

Proponents of CBD tout a wide array of health benefits, including treating anxiety and reducing the frequency of convulsive seizures in people with epilepsy. 

CBD is also commonly linked to eye health and treating glaucoma. However, CBD and medical marijuana are not effective ways to treat glaucoma or other eye conditions. 

What Exactly Is CBD?

Cannabinoids are the substances that make up a cannabis plant. The average plant will contain more than 100 cannabinoids. 

The most common cannabinoids are tetrahydrocannabinol (THC) and CBD. THC is responsible for most of the psychological effects that a person experiences if they use marijuana. 

CBD, however, does not cause any psychological or impairing effects. This means that ingesting the chemical will not leave a person feeling the same effects as taking a product that contains THC. 

CBD can help make a person feel more relaxed and comfortable without the feeling of euphoria or confusion, which are often associated with the consumption of products containing THC. Supplemental products that contain CBD are typically legal, and the FDA has approved a purified form of the chemical that helps to treat seizures. 

In addition to being a potential medicine for epileptic seizures, the connection between CBD and eye health is also gaining popularity. 

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How Does CBD Affect the Eyes?

There is ongoing research to determine exactly how CBD affects the eyes. There is not a whole lot currently known, but several studies have shown that CBD does have anti-inflammatory effects on the eyes.

There are several medical conditions eye doctors commonly treat that cause inflammation, including these:

• Cataracts
• Glaucoma
• Macular degeneration
• Allergies
• Meibomian gland disease

CBD could potentially be utilized to ease the inflammation of these conditions, but the chemical is not usually a doctor’s first choice. Instead, an ophthalmologist or other health professional will recommend an anti-inflammatory medication, such as corticosteroid. 

Corticosteroids are a group of steroid hormones that are produced in the adrenal cortex and can also be made synthetically. They are typically given in the form of eye drops and have been proven to ease inflammation in the eyes.

There is also some evidence that CBD can protect nerves from damage and relieve neuropathic pain, possibly making it a viable choice for patients with optic neuritis, glaucoma, and other types of eye disorders that are associated with the optic nerve.

CBD & Glaucoma

Contrary to actual studies that say otherwise, cannabis has long been associated with relieving glaucoma symptoms. Patients with glaucoma typically experience high levels of intraocular pressure (IOP). Too much extra fluid pressure damages the optic nerve and can cause vision loss and blindness.

The THC in cannabis lowers IOP in patients with glaucoma for small amounts of time. This can lead to temporary relief, but it is not substantial enough to be an effective treatment. A patient with glaucoma would have to consume enormous amounts of THC daily for it to have the same pressure-relieving effects as current glaucoma eye drop treatments. 

CBD may protect against cell damage, but studies have indicated that the chemical has no influence on IOP levels. Other studies have shown that CBD actually increases IOP levels, which can make the glaucoma and associated pain from the pressure even worse. When the pressure in the eye becomes so severe that it starts to damage the optic nerve, gradual vision loss begins to occur. 

What Can CBD Do for the Eyes?

In addition to increasing IOP levels and having effects on inflammation and nerves, CBD has also been shown to affect the level of activity of both oxidants and antioxidants. Oxidants can react with other cellular molecules and cause various diseases, including macular degeneration. 

CBD and its antioxidative qualities can theoretically help to reduce the risk of macular degeneration. However, lutein and zeaxanthin, which can be found in leafy green vegetables, are the most potent antioxidants for preventing or reducing the risk of macular degeneration.

CBD may have the potential to be an antibacterial compound. Current antibiotics are slowly becoming resistant to bacteria, so the antibacterial nature of CBD could possibly be an alternative in the future. This would be beneficial for eye diseases that result in the growth of bacteria, including conjunctivitis and blepharitis.  

Can CBD Cause Any Eye Problems?

There is still ongoing research, but CBD does not appear to cause any problems with healthy eyes. CBD can increase intraocular pressure, which can make symptoms worse for people who have glaucoma. 

In more severe cases of glaucoma, the increased pressure damages the optic nerve and starts to cause blindness. However, CBD has not been proven to actually cause glaucoma on its own, and there is no direct link between CBD and the eye’s optic nerve. 

Other Health Concerns With CBD

Even though CBD is legal and widely considered to be safe, there have been reports of side effects after ingesting products containing CBD. These side effects include the following:

• Gastroenteritis
• Dry mouth
• Fatigue
• Drowsiness
• Reduced appetite

CBD’s Interference With Other Medications

CBD can have a negative reaction with certain medications. Many medications are processed in the body by being broken down by the liver’s enzymes. CBD is processed the same way, so it can interfere with these enzymes. This can result in a person potentially having either too much of a medication in their system or not enough.

Studies have identified over 50 medications that could potentially have dangerous side effects when mixed with products containing CBD or THC. Specifically, products containing only CBD without any THC may have negative side effects when a person is already taking these medications:

• Warfarin, which prevents blood from clotting and is typically prescribed to people who have suffered a stroke
• Amiodarone, which slows the nerve impulses in the heart and helps people with irregular heartbeats
• Levothyroxine, which helps treat an underactive thyroid gland
• Clobazam, lamotrigine, and valproate, which are all used to combat seizures

What Are the Benefits of CBD?

Research has suggested that CBD might help people fall asleep and stay asleep throughout the night. 

CDB proponents often claim that several illnesses and ailments can also benefit from products containing CBD. Both animal studies and research in humans suggest that CBD could be beneficial in treating these conditions:

• Anxiety and depression
• Autoimmune diseases
• Migraines
• Inflammation
• Arthritis and chronic pain
• Insomnia
• Addiction

However, research is ongoing, so many of these claims currently lack sufficient evidence. CBD is typically sold as an unregulated dietary supplement, not a medication prescribed by a medical professional.

CBD & Epilepsy

The FDA has approved a CBD medication known as Epidiolex that helps treat seizures associated with certain types of epilepsy. Epidiolex helps to calm the brain cells that cause seizures while also inducing anti-inflammatory effects. 

Despite the medication’s growing popularity and positive effects, the most commonly used treatments for epilepsy are still anti-epileptic drugs that are able to change the levels of chemicals in the brain.  

CBD & Eye Health FAQS

Does CBD make your eyes red?

CBD does not cause redness in the eyes. THC, the other active ingredient present in cannabis, does cause red and watery eyes, but there is no connection between CBD and red eyes or inflammation.

Does CBD make your eyes sensitive to light?

An eye’s sensitivity to light is not affected by CBD. Sensitivity to light can be caused by strained or dry eyes or other conditions such as eye trauma or eye infections.

Is CBD good for dry eyes?

CBD is not a good treatment for dry or irritated eyes. Instead, eye drops and other lubricating products are recommended to treat dry eyes.

Can CBD make your vision better?

CBD cannot improve a person’s vision. While corrective lenses, like glasses or contact lenses, and eye surgery like LASIK can correct vision, many vitamins and antioxidants can support overall eye health and vision.

References

1. Age-Related Macular Degeneration. (September 2019). Minnesota Department of Health.

2. Antioxidative and Anti-Inflammatory Properties of Cannabidiol. (December 2019). Antioxidants.

3. Cannabis (Marijuana) and Cannabinoids: What You Need To Know. (November 2019). National Center for Complementary and Integrative Health. 

4. Cannabinoids in the Treatment of Epilepsy: Hard Evidence at Last? (December 2017). Journal of Epilepsy Research.

5. Cannabinoids Suppress Inflammatory and Neuropathic Pain by Targeting α3 Glycine Receptors. (June 2012). Journal of Experimental Medicine.

6. Cannabidiol (CBD): What We Know and What We Don’t. (September 2021). Harvard Health Publishing.

7. CBD Oil May Worsen Glaucoma. (February 2019). American Academy of Ophthalmology.

8. CBD and Other Medications: Proceed with Caution. (January 2021). Harvard Health Publishing.

9. Corticosteroids. (July 2022). StatPearls.

10. Emerging Use of Epidiolex (Cannabidiol) in Epilepsy. (2020). The Journal of Pediatric Pharmacology and Therapeutics.

11. Glaucoma: Etiology, Pathophysiology and Management. (September 2020). Biomedical Journal of Scientific & Technical Research.

12. Nutrients for Prevention of Macular Degeneration and Eye-Related Diseases. (April 2019). Antioxidants.

13. THC Regulates Tearing via Cannabinoid CB1 Receptors. (August 2020). Investigative Ophthalmology and Visual Science.