What do CBD, cannabis, and marijuana have do with with optometric care? Find out. Are you worried about whether CBD will give you noticeably red or dry eyes? Here are the factors you’ll want to understand about CBD’s effects! Cannabis CBD eye drops There are at least 113 different cannabinoids that have been isolated from the cannabis plant. The most notable, are THC and CBD. THC exerts its effects by binding to
Cannabis and CBD oil: a new “old” friend in optometry
Optometric training requires learning about bones, muscles, neurology, and the vascular and other systems. But have you heard of the endocannabinoid system (ECS)?
If the answer is no, that’s not surprising.
Although the ECS is critical for human survival, 1,2 cannabinoid receptors weren’t identified until 1964, 1-4 when investigators were trying to locate where marijuana tetrahydrocannabinol (THC) interacted with the brain. It wasn’t until 1988 that the ECS was identified, and 1992 when it was officially acknowledged. 2-4
Humans operate on the parasympathetic and sympathetic system. The parasympathetic system operates under “normal” conditions.
When the body perceives it is under attack, neurochemicals trigger the sympathetic system, activating the “fight or flight” response. 5,6
The ECS, simply put, disengages the sympathetic system. It is responsible for bringing the body back into balance (homeostasis). 2,7 If it doesn’t, the body is faced with unresolved “danger” from the chemicals and processes that are designed to protect it. These chemicals cause inflammation and begin attacking and damaging the body, 7,8,9 which is then labeled as “such and such” disease. Our rampant, epidemic health problems are self-inflicted, 5,7,10 brought on by our diet, lifestyle, and technology. 7,10,11
The ECS (Figure 1) is made up of 2 main receptor sites, CB1 and CB2. 2,4,7,10
CB1 sites are primarily in the brain, heart, and lungs, and modulate the immune response. CB2 receptors are primarily located in the lymph system, detoxification organs, and peripheral systems to break down and clear out the toxic immune system chemicals and debris. 1,3,7,14,24
The body produces its own chemical—anandamide, known as the bliss chemical—to regulate our systems via the ECS. 7,13,14 Unfortunately, in today’s high-stress environment, it can’t create enough to keep up with the demand. 10,14
Eating dark chocolate, exercising, or being “in the zone” are other ways to feed the CB1 and CB2 receptors. 7,14 Cannabidiol (CBD) was removed from livestock feed when it was made schedule 1 in 1941, so it has not been in the food chain for 80 years. CBD is nature’s external equivalent to supplementing the body’s anandamide shortage. 17,18,24
Technically, cannabis is not marijuana; nor is CBD. Cannabis is the botanical name for the common hemp plant, which has been cultivated for industrial purposes for more than 20,000 years. 15,18,24
The medicinal properties of hemp have been utilized for over 10,000 years. 15 The 2 main classes of cannabis are sativa, which is generally stimulating, and indica, which is generally calming. 16,18
Marijuana is a small subset of hemp that has been bred to produce more “high.” Hemp has over 400 different chemicals, with 100 compounds known as cannabinoids, each creating various effects. 16,18
CBD is one of the most prevalent cannabinoids in the hemp plant; it has the most profound, diverse, and beneficial impact. 16,18 The main takeaway is that cannabis is really just the hemp plant, and CBD is not marijuana.
THC and CBD originate from the same compound and have nearly identical chemical structures (Figure 2). 16,22 Depending on the genetic strain, the hemp will have higher or lower THC and CBD levels. When the flower is beginning to bloom, however, growers must test the plants daily because the CBD in the plant will start to become THC. 16,22
At that point, the growers only have 48 hours to harvest their crop. The legal amount for THC to not be considered marijuana is 0.3%. 19,22
The CBD industry wants as high an amount of CBD as possible with the least THC possible. CBD’s profound effects on all bodily functions are not forced—unlike those of pharmaceutical agents—and nor does the chemical have their toxicities or unintended adverse effects (Figure 3). 20,21,24
As of February 2022, 37 states in the United States have legalized marijuana for medical use and 18 have legalized it for recreational purposes .20 The medical and recreational marijuana market is projected to be $30 billion in 2022. 21
Although marijuana still has legal hurdles to overcome, the CBD market is legal in all 50 states. 22 CBD is also available OTC and thus is free from FDA regulations and red tape. 22 The CBD market is projected to be $2 billion in 2022. 23
This projection will result in both good and bad consequences. Because cannabis has been outlawed as a Schedule 1 drug for 80 years, little controlled research has been undertaken and no distinction made between the effects of THC and those of CBD.
Medical benefits, risks
Much of marijuana use is for the high it produces, but there are some documented medical benefits. These include the relief of pain and nausea related to cancer treatments, aiding of sleep issues, reduction of posttraumatic stress disorder symptoms, easing of symptoms in those withdrawing from opioid addiction, and a calming of symptoms of various neurological conditions. 4,24
Unfortunately, according to more recent findings, marijuana does interfere with cognitive ability, 24,29 damages memory function, and destroys brain tissue. It also causes heart attacks—even in younger people with no underlying conditions—may have negative effects on genetics and pregnancy, and, if ingested by vaping or smoking, increases cancer risks. 24 Thus, marijuana is far from risk free.
Of more direct concern to optometrists are the negative effects of marijuana on the visual system. Both photopic and scotopic vision are impaired due to decreased macular and peripheral sensitivity. 24-35
Neurologically, vision processing is compromised, creating selective scotomas and interfering with one’s ability to navigate in the environment. 24,26-28,30,32-35
The eye is both a specialized neurologic receptor and a person’s primary connection to the physical world. It is important for optometrists to be aware of CBD, as eyes are packed with both CB1 and CB2 receptors.
Consider the major 5 medical conditions optometrists often encounter with when working with patients:
1. Cataracts 37
2. Glaucoma 38,39
3. Macular degeneration 41-43
4. Allergies 46
5. Meibomian gland disease 47
Although each is a separate condition, all have inflammation as the root cause due to the eye being threatened by the environment. 35,40 Many treatments are based on treating the symptoms or slowing the progression of damage by interfering with the ocular response process.
CBD works with the body’s natural system to decrease the inflammation process and restore homeostasis, avoiding the long-term results that define disease.
Peer-reviewed, evidence-based science is limited. However, I have heard anecdotally that some patients have experienced better vision with OTC supplementation of CBD and ocular nutraceuticals, backed by macular pigment ocular density (MPOD), optical coherence tomography (OCT), retinal photographs, and acuity. 43,44
We have accepted that ocular “aging” conditions are normal, inevitable, and unstoppable. 45,57 Perhaps traditional medical treatments would be less necessary if we worked with the natural body system designed to minimize those issues.
Beyond ocular conditions, optometrists must step back and look at the larger medical issues facing humanity.
Obesity, diabetes, blood pressure, heart disease, cancer, Alzheimer disease/dementia, autoimmune conditions (lupus), rheumatoid arthritis, fibromyalgia, multiple sclerosis, neurologic disorders, depression, anxiety, panic attacks, migraines, attention-deficit/hyperactivity disorder, and concussions are all inflammation-related processes caused by an increased assault on our physical system.
This has overloaded the natural mechanism eyecare professionals were designed with to maintain health. Optometrists need to learn about ECS and CBD to augment their toolbox for taking care of patients’ well-being. 6,9,36,48,51,55,56,59-63
CBD Oil For Dry Eyes
Cannabis, especially marijuana, is often associated with red eyes in the collective imagination , especially regarding smoking. Marijuana smokers can often be easily identified by the red rings around their eyes, along with characteristics like drowsiness, euphoria, and sometimes excessive hunger also called the munchies. However, people need to understand that THC, not CBD, causes inflamed, watery, and red eyes. But why is that the case? And will CBD ever make your eyes red or dry?
Our cannabis and CBD experts at Care Division are here to explore these essential questions to help you better understand the impacts CBD has on your body. Please continue to learn everything you’ll need to know about the issue, and also consider exploring our selection of other educational CBD resources for even more information. We’re proud to provide people not only with top-quality CBD products but critical knowledge about CBD as a whole.
Why Doesn’t CBD Cause Red or Dry Eyes?
You’ll first want to understand that CBD will not turn your eyes red or dry, no matter how much you smoke, consume, or put on your body, because it doesn’t cause the same effects as THC. They are two different cannabinoids that trigger a diverse range of symptoms in those who smoke or consume them, despite being found in the same plant. To better explain the situation, let’s delve into the primary differences between THC vs. CBD .
The Basics of THC
THC is the well-known psychoactive component of cannabis that results in a sensation of being “high” or euphoric, but it also causes other symptoms, including red, irritated eyes. This effect occurs because THC dilates blood vessels and lowers blood pressure while ultimately causing the usually small, unnoticeable blood vessels in the eyes to appear more prominent. The higher blood flow in the eyes then triggers excess redness, watering, and irritation, creating the telltale look associated with marijuana smokers. However, the smoke produced from marijuana pipes or joints may also exacerbate eye redness and irritation.
The Basics of CBD
In contrast, CBD is a nonpsychoactive cannabinoid that will not get users high and instead produce a range of other, often beneficial symptoms . CBD is often used to help people relieve pain, relax, and sleep well without altering their mental states. It also doesn’t cause the same effects on blood vessels as THC or cause blood to rush to the eyes. If someone smokes or consumes CBD or CBD-based products, those around them are not likely to notice, as they likely would when someone smokes or consumes THC.
However, please keep in mind that too much of anything can be bad for you, so be sure you don’t go overboard. Just because it’s harder for others to tell if you’ve been smoking or consuming CBD products compared to THC ones doesn’t mean you should go too far. Consider reading our specialized guide on how much CBD is too much and the effects it can cause to learn more.
With so many different CBD products on the market, it can be hard to find the best ones to try first! Care Division can help save you some time by offering access to a wide array of top-quality CBD tinctures, topicals, and beauty products you won’t find anywhere else!
Used CBD and Still Got Red, Dry Eyes? You May Have Been Scammed
If you’ve ever smoked CBD or consumed a CBD product that you thought was THC-free and still ended up with red, irritated eyes, then it wasn’t actually THC-free. Throw the product out right away if you genuinely don’t want to deal with those effects or have THC in your system.
Try using eye drops to relieve the inflammation, and consume things like coffee, chocolate, and salt to help narrow your blood vessels. You’ll generally need to be patient and wait for the issue to resolve itself , but those tactics can sometimes help speed up the process.
You always want to be careful about where you get your products, what brand they belong to, how much they cost, and other critical factors that can help you determine the quality of the product. You’re more likely to encounter this kind of issue if you get your CBD from a friend or an uncertified seller, so always be sure you’re getting your flower and other products from quality, trustworthy sources, like Care Division.
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Cannabis CBD eye drops
There are at least 113 different cannabinoids that have been isolated from the cannabis plant. The most notable, are THC and CBD.
THC exerts its effects by binding to CB1 and CB2 receptors in humans. CBD does not act on the cell wall, but rather inside the cell. It is for this reason that CBD has no addictive potential, no psychoactive activity, no withdrawal, and no toxicity.
CBD has multiple health benefits for insomnia, anxiety, depression, seizures, autism, pain, social anxiety, addiction, and many more. Recent studies show that CBD can also help in the treatment of some eye conditions.
CBD is alleged to be particularly beneficial on the eye due to its neuroprotective effects. Preventing apoptosis of the optic nerve cell can preserve vision, the ultimate goal in the treatment of all diseases of the eye.
The challenge of using a topical cannabis product on the eye
CBD is a natural oil, and as such, is lipophilic. The cornea which is the first layer of the eye is coated with a hydrophilic layer. On a mechanistic level, it is challenging for an oil-based substance to successfully pass through the water-based liquid lining the cornea and penetrate the eye.
One idea that is being investigated is the use of liposomes. Liposomes have hydrophilic heads and hydrophobic tails that line themselves up into a sphere. Current studies have demonstrated that topically applied CBD in a liposomal formulation can successfully penetrate the hydrophilic layer that lines the cornea.
Why use topicals cannabis product when there are other delivery systems available?
Topicals will eliminate all systemic side effects and maximize the dose delivered to the eye.
The problem, as with all topicals, is that less than 5% of any dose delivered reaches the intraocular tissues. The surface of the eye is moistened by fluid which is constantly flushing the surface of the eye and drains out through the lacrimal duct. In addition, any medication administered must first penetrate the hydrophilic layer that coats the cornea and following that, the lipophilic corneal lining.
CBD and corneal abrasions
When the cornea is damaged, there is intense pain due to a dysfunction in the sensory receptors that line the cornea. As a result of the physical disruption from the abrasion, intense inflammation develops. Both THC and CBD can provide analgesic and anti-inflammatory benefits, but THC is limited due to its psychoactive effects which may include dysphoria, disruption of short-term memory, cognitive impairments, sense of time distortion, and reduced coordination. CBD however, can provide the analgesic and anti-inflammatory benefits without any psychoactive side effects.
What ultimately causes visual loss and how can cannabinoids prevent it?
Visual loss is caused by ischemia of the optic nerve – which is seen in diabetic retinopathy, or by increased pressure on the optic nerve, essentially crushing the nerve – which is seen in glaucoma.
Cannabinoids decrease ischemia and improve oxygen delivery to the optic nerve by decreasing glutamate release. Glutamate activates NMDA receptors which cause calcium influx into cells, frees radical generation, and subsequent cell death. CBD can prevent the death of nerve cells by scavenging the toxic reactive oxygen radicals released by glutamate activation.
In glaucoma, there is increased intraocular pressure which eventually crushes the optic nerve. Cannabinoids have vasorelaxant properties and as a result, decrease the intraocular pressure by dilating the capillaries thus promoting increased exit flow of the aqueous humor.
What medical benefit does CBD offer that other topical agents do not?
As an example, the most common ocular injury – corneal abrasions, is treated with a myriad of agents which include topical corticosteroids, tricyclic antidepressants, opioids, and agents that stimulate the GABA receptors. All of these pharmacotherapeutic agents are suboptimal and have side effects.
Studies were performed on mice models given experimentally induced corneal surface injuries. When topical CBD was administered, corneal pain and inflammation were reduced via activation of the 5-HT1A receptor. CBD provides adequate pain relief and reduces the inflammation and does so without any of the side effects seen in conventional agents.
CBD & diabetic retinopathy
Diabetic retinopathy is one of the retinal diseases associated with vascular neuroinflammation. It is the leading cause of blindness in the Western world and treatment options are very limited.
Diabetes causes superoxide formation which leads to the release of adenosine and pro-inflammatory cytokines. In preclinical studies, CBD was found to block superoxide formation. CBD produced the antioxidants that reduced the inflammation in the damaged retina of the diabetic.
CBD and dry eyes
The major cause of dry eyes is a dysfunction of the meibomian gland. The meibomian gland is located behind the eyelashes on both the top and lower eyelids. The fatty substance they produce slows the evaporation of the tears. This lack of oil production results in inadequate tear production with the clinical manifestation of dry eyes. CBD applied topically can help restore the function of the meibomian glands and reduce dry eyes.
Another cause of dry eyes is corneal neuralgia – also treated by CBD. In corneal neuralgia, the corneal nerves become dysfunctional and send pain signals to the brain that are out of proportion to the physical insult, if indeed there is any injury at all. The brain perceives the sensation known as ‘dry eyes.’ CBD applied topically eliminates the neuralgia of the pain felt from the dry eyes.
Future research on CBD and Cannabis eye drops
Work is underway to find the best microemulsions and cyclodextrins so that CBD, a lipophilic agent, can penetrate the hydrophilic aqueous fluid that continually washes the surface of the cornea.
Take home points about Cannabis CBD eye drops
Inflammation leads to damage to the cornea, uvea, retina, and ultimately to the optic nerve.
When inflammation is not blocked, it leads to apoptosis of the optic nerve or death of the cell, in other words – blindness.
CBD can address the inflammation and we believe, can help prevent the endpoint of all ocular diseases which is blindness.
About Cannabis GxP consultancy
Cannabis GXP is an Israel-based consultancy firm working within the cannabis industry.
We are currently engaged in revolutionizing the world of cannabis and hemp cultivation, production and regulation, and are reaching out to growers and manufacturers across the world who wants to join this amazing ride.
We are proud to stand at the forefront of the GMP standards and regulation fields in Israel and worldwide.
Our team is compelled to spread the message of the importance of cannabis regulation and standardization as the world enters a new era of cannabis legislation.
We aim to position our clients with their best foot forward when it comes to anything and everything cannabis related.
We assist companies and growers with facility design, Quality Assurance, Good Practices (GAP/GMP/GLP/GDP), training, and dealing with local and global regulation. Cannabis GXP strives to assist our clients with the development, manufacture and distribution of pharma-grade cannabis products, with a strong emphasis on safety, efficacy, and professionalism.
Cannabis GXP is a subsidiary company of Bio-Chem Ltd. (2007) – a consultancy company for Pharmaceutical, Medical Devices, Cosmetics, and Supplements, based in Israel (http://bio-chem.co.il/en/home/)
Some of our esteemed clients: Teva, Tikun Olam, J&J, Weizmann Institute of Science, BOL pharma, Seach, Nuuvera, Gamma-Cert, Cannabillis, Monsanto, Evogene, Collplant, Sigma-Aldrich, and many more.
Our Cannabis consultancy services include:
- Investigational Cannabis product development and clinical trials
- Cannabis growing & manufacturing facilities design
- Cannabis Quality Assurance & Good practices (GxP)
- Cannabis product manufacturing technology
- Cannabis product regulation & FDA/EU submission
- Novel Cannabis APIs and product delivery systems
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“The Cannabinoids Δ 8 THC, CBD, and HU-308 Act via Distinct Receptors to Reduce Corneal Pain and Inflammation.” Cannabis Cannabinoid Res. 2018; 3(1): 11–20.
“Anti–Inflammatory Effects of Cannabinoids in Endotoxin–Induced Uveitis.” Investigative Ophthalmology & Visual Science May 2005, Vol.46, 972
“Neuroprotective Effect of(−)Δ 9 -Tetrahydrocannabinol and Cannabidiol in N-Methyl-d-Aspartate-Induced Retinal Neurotoxicity: Involvement of Peroxynitrite.” The American Journal of Pathology Volume 163, Issue 5, November 2003, Pages 1997-2008
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“Turning down the thermostat: modulating the endocannabinoid system in ocular inflammation and pain.” Front Pharmacol. 2016;7:304