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 (

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



 “Intraocular distribution of topically applied hydrophilic and lipophilic substances in rat eyes.”  Drug Delivery. 2016 Oct;23(8):2765-2771.

 “Increase in aqueous solubility, stability and in vivo corneal permeability of anandamide by hydroxypropyl-β-cyclodextrin.” Int J Pharm (1996); 137:209–17.

 “Anti–Inflammatory Effects of Cannabinoids in Endotoxin–Induced Uveitis.”  Investigative Ophthalmology & Visual Science May 2005, Vol.46, 972

“Efficacy of cannabidiol and cannabidiol derivatives in the treatment of ocular pain.”  International Cannabinoid Research Society 26th annual symposium. (2016) 26 (1), 24.

“The Non-psychoactive Phytocannabinoid, Cannabidiol (CBD), and the Synthetic Derivatives, HU308 and CBD-DMH, Reduces Hyperalgesia and Inflammation in a Mouse Model of Corneal injury.”  FASEB Journal of  Pharmacology    Published Online: 1 Apr 2017  Abstract Number: 811.7

“The Cannabinoids Δ8THC, 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(−)Δ9-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

“Cannabidiol inhibits inducible nitric oxide synthase protein expression and nitric oxide production in β-amyloid stimulated PC12 neurons through p38 MAP kinase and NF-κB involvement.”  Neuroscience Letters   Volume 399, Issues 1–2, 15 May 2006, Pages 91-95

“Turning down the thermostat: modulating the endocannabinoid system in ocular inflammation and pain.” Front Pharmacol. 2016;7:304