If you’ve ever found yourself scrolling on the holistic side of TikTok or Instagram, there’s a high likelihood you’ve seen videos touting the many miraculous effects of castor oil. From curing presbyopia, cataracts, and glaucoma to dissolving floaters, castor oil has become a popular cure-all natural remedy.
Though not a new discovery in medicine, the resurgence of castor oil for use in ocular health has prompted intrigue from patients and concern from eyecare providers. This article explores castor oil’s potential impact on eye health, its history, legitimate applications, and the myths perpetuated online.
What is castor oil?
Castor oil is derived from the seeds of the Ricinus communis plant. Known for its high concentration of ricinoleic acid (a monounsaturated fatty acid), castor oil use dates to Ancient Egypt.1 Through the centuries, it has been used as a laxative, anti-inflammatory agent, skin treatment, and more.
It is presently used in the food industry as a mold inhibitor and preservative, in the cosmetics industry as a moisturizer, and in modern medicine as a vehicle for administering steroid hormone injections.2 Finally, in optometry/ophthalmology, castor oil is a component in lipid-based artificial tears.
However, not all castor oil is created equal. Many cosmetic-grade products contain additives, contaminants, or are not sterile, raising serious safety concerns when used near or in the eyes.
Debunking the myths about castor oil and ocular diseases
1. Castor oil reverses presbyopia
There is currently no scientific evidence to support the claim that castor oil can reverse near vision blur (presbyopia).3 While it may provide some benefits for youthful, glowing skin, castor oil cannot restore accommodation or improve near vision. At most, users may experience a temporary improvement in vision/visual comfort from enhanced tear film quality.
2. Castor oil dissolves cataracts
Claims that castor oil can dissolve cataracts are not supported by peer-reviewed research.3 Cataracts are caused by the breakdown and clumping of lens proteins, largely due to aging, with other factors accelerating their formation and development.
No topical treatment has been proven to reverse this process. Current cataract treatment remains strictly surgical.
3. Castor oil lowers intraocular pressure in glaucoma
There is no evidence that castor oil reduces intraocular pressure.4 Current glaucoma treatments may involve eye drops, laser therapy, filtering surgery, drainage tubes, minimally invasive glaucoma surgery (MIGS), or any combination of those options.
Though there are potential alternative approaches to glaucoma treatment, they require significantly more research and development, and castor oil isn’t on the list.
4. Castor oil dissolves floaters
There’s no scientific evidence that castor oil reduces the appearance of floaters.3 Castor oil is unable to penetrate the layers of the cornea to reach the vitreous or any other interior ocular structures. If a true cure for floaters existed, it would be widely adopted and promoted by eyecare professionals.
Castor oil and dry eye disease: A valid use
The most evidence-supported ophthalmic use of castor oil is for evaporative dry eye disease, especially in the context of meibomian gland dysfunction (MGD).5 Castor oil is found in lipid based artificial tears because of its ability to enhance the lipid layer of the tear film and reduce tear evaporation, creating a healthier ocular surface and more comfort for the patient suffering from dry eye symptoms.
A study published in Ophthalmology found that castor oil-containing eye drops significantly improved tear film stability in patients with MGD.5 By enhancing ocular surface stability, castor oil, combined with other lubricating ingredients like glycerin, may help alleviate symptoms like burning, irritation, and fluctuating vision.
Ophthalmic-safe over-the-counter products such as Refresh Optive Mega-3 and Blink Triple Care incorporate castor oil in their formulations. Prescription-strength options like Restasis and Cequa contain castor oil as well. Additionally, topical sterile castor oil around the lids can improve periocular skin health and may aid in managing blepharitis.6
One study showed that after 28 days of castor oil treatment on only one eye (using the other eye as the control), Ocular Surface Disease Index (OSDI) scores significantly reduced.
Clinical improvements were noted, such as decreased:6
- Lid margin thickening
- Telangiectasia
- Eyelash matting
- Madarosis
No adverse effects were recorded; however, it should be noted that the sample size of this study was quite small.
Safety concerns and misuse
Despite its benefits in regulated formulations, non-sterile castor oil poses a real risk of infection when applied directly to the eye, including:7
- Allergic conjunctivitis
- Microbial keratitis
- Corneal toxicity
- Contact dermatitis
Castor oil that is not specifically formulated for ophthalmic use may contain dyes, preservatives, fragrances, or other ingredients that can cause irritation and infection when used in and around the eyes. Another study suggests that castor oil is cytotoxic to conjunctival cells, resulting in significant necrosis.8
Social media and misinformation
Platforms like TikTok and Instagram have amplified the spread of health misinformation. Videos claiming castor oil can cure glaucoma or restore eyesight lack scientific credibility but still go viral, reaching millions of people.4
Research published in JAMA emphasizes the dangers of health-related misinformation, noting that false health claims are shared more widely and rapidly than fact-based content.9
As eyecare professionals, we have a responsibility to educate patients about the legitimacy of these internet claims and offer evidence-based alternatives. The eyes are too valuable and too delicate to allow patients to fall victim to unsubstantiated internet claims.
To learn more about common misinformation in eyecare and how to address it, check out Top Eyecare Myths and How ODs Can Debunk Them!
Key takeaways
- Castor oil is not a cure for presbyopia, cataracts, or glaucoma. Claims suggesting otherwise are unsupported by science.
- Castor oil has proven uses in artificial tears and eyelid treatments, particularly for dry eye disease and meibomian gland dysfunction.
- Non-sterile castor oil is unsafe for ocular use and may lead to infections or allergic reactions.
- Social media is a significant source of misinformation, and viral trends should never replace professional guidance.
- Ongoing research may expand castor oil's ophthalmic uses, but current benefits are limited to approved, sterile, pharmaceutical-grade formulations.
