Fungi, Worms, and More: Hidden Dangers of Soils on Eye Health

Our eyes are constantly exposed to environmental threats, making them highly susceptible to infections and diseases. Dust, wind, air pollutants, and chemicals can damage the eyes’ natural protective barrier, which can only do so much in the first place. It’s up to us to protect and maintain optimal eye health, especially against overlooked factors like the soil beneath our feet.


Viral and Parasitic Eye Infections From Soil Organisms

Of all the foreign invaders that can wreak havoc on our delicate eyes, pathogens are among the most dangerous. These living, microscopic creatures can cause serious infections, leading to corneal ulcers and permanent vision loss. Making matters worse, pathogens are invisible to the naked eye, and they are everywhere.

In particular, the soil is home to trillions of pathogens. These microorganisms include parasitic protozoans that use the eyes as a portal of entry, fungi capable of infiltrating the eyes as spores, and parasitic worms that can invade the eyes as larvae. Below, we will delve into each of these cases and explore the latest clinical findings.


1. Acanthamoeba Keratitis

Acanthamoeba is a unicellular, free-living amoeba. Exposure to the organism can cause a severe eye infection called Acanthamoeba keratitis. According to the Centers for Disease Control and Prevention (CDC), coming into contact with Acanthamoeba is common, and only some develop a disease or infection from exposure. However, when Acanthamoeba keratitis occurs, it can lead to permanent visual impairment or blindness.

The dominance of A. castellanii in environmental and corneal swab samples from a 2018 study suggests it may be the most harmful strain. Researchers concluded that contaminated dry soil or dust is the primary source of Acanthamoeba infection in the corneas of cats and dogs in Malaysia. The study did not involve humans, but many conditions that develop in canines and felines can affect people – Acanthamoeba keratitis included.


2. Endophthalmitis

Recovering from ocular surgery or sustaining a recent eye injury can invite more pathogens into the eyes, especially without proper care.

For example, a fungus called Fusarium dimerum may infiltrate the eyes. Commonly found in soil and plants, contact can cause endophthalmitis – an intraocular inflammatory disease affecting the eye’s internal structure, including the vitreous humor (a gel-like substance inside the eye) and the aqueous humor (the fluid in the front part of the eye). Immediate treatment with antibiotics and antifungal medication (topical natamycin) is necessary to prevent further damage to the eye and preserve vision.


3. Helminthic Infections

Parasitic worms called helminths – commonly found in the soil of warm, moist climates where hygiene and sanitation are poor – are notorious for causing pancreatitis, mechanical intestinal obstruction, gastrointestinal hemorrhage, and other severe health complications. Helminths can also invade the eyes, causing impaired eye movement, pain, sensitivity to light, and eventual blindness

Treatment for parasitic eye infections varies depending on the type of parasite responsible. In most cases, oral or topical medications like pyrimethamine, ivermectin, and diethylcarbamazine can address parasitic infections. However, in some cases, surgical removal of adult worms may be necessary.


4. Microsporidial Keratoconjunctivitis

While participating in outdoor recreation, dust particles can rise and bring pathogens with them. In rare cases, an outbreak occurs, which is precisely what happened in Singapore over a decade ago.

Between ten to 30 days following two consecutive rugby matches, 25 teens contracted microsporidial keratoconjunctivitis. The symptoms observed include:

  • Multiple superficial coarse punctate keratitis: the presence of small and coarse white or grayish spots on the surface of the cornea
  • Keratitic precipitates: small clusters of white blood cells or inflammatory cells that accumulate on the inner surface of the cornea
  • Increased intraocular pressure

Corneal scrapings and subsequent PCR tests confirmed infection from an obligate intracellular fungus called Vittaforma corneae. Exposure to soil or water contaminated with the fungus may have caused the outbreak. Fortunately, all patients recovered following treatment with fluoroquinolone and other antiseptics.

Related: How to Protect Your Eyes While Playing Sports


Chemicals Affecting the Eyes

Aside from pathogens, the eyes are also vulnerable to chemicals in the environment. Some may feel a painful, stinging sensation upon contact, while others may stay oblivious until vision changes arise. Here are the chemicals and compounds responsible:

1. Chromium

Chromium is an environmental pollutant present in air, water, and soil. Chromium (VI) compounds, in particular, have toxic and carcinogenic effects. They can cause several diseases and affect different organs, including the kidneys, liver, skin, and eyes. 

Sicca syndrome, also called Sjogren’s syndrome, develops from excessive chromium exposure. This systemic autoimmune disease affects the entire body. Dry eyes, dry mouth, and musculoskeletal pain are the most common symptoms.

In a 2018 study involving 11,220 farmers, the researchers found that every 31 of 105 farmers (55.01 for women and 5.59 for men) had Sjogren’s syndrome. The highest prevalence of sicca syndrome was in an area where farm soils contained high levels of chromium, suggesting that chromium presence in soil may increase the incidence of sicca syndrome – an incurable disease affecting the entire body, including the eyes.


2. Chlorine

Chlorine is a popular chemical for eliminating specific pathogens, with pool owners worldwide using it to kill germs. Many residential and commercial property owners also use chlorine dioxide for soil disinfection. However, chlorine damages the eyes, suggests a growing body of preliminary studies. Some researchers also believe that chlorine is more harmful than pathogens.

Excessive exposure to chlorine can cause several eye-related problems, including:

  • Conjunctivitis: This infection, which can be bacterial or viral, thrives in water and can cause itchy, irritated eyes, severe redness, and crusting.
  • Red eyes: Chlorine can dehydrate your eyes and remove the tear film, leading to redness.

While conjunctivitis and red, dehydrated eyes do not cause permanent vision problems, they can cause damage in rare cases if symptoms are severe and neglected. Wearing goggles when swimming in chlorinated pools and opting for natural soil disinfectants can protect your eyes and body from potential health risks.

Certain organisms and chemicals lurking beneath the soil play a crucial role in impairing vision. Aside from following preventive measures, remember to schedule regular checkups with your Sun City eye doctor. After all, if something is wrong with your eyes, catching it early can make all the difference in how your treatment plan will go. Contact Arizona Retinal Specialists today.

NOTICE TO USERS is not intended to be a substitute for professional advice, diagnosis, medical treatment, or therapy. Always seek the advice of your physician or qualified health provider with any questions you may have regarding any health symptom or medical condition. Never disregard professional medical advice nor delay in seeking professional advice or treatment because of something you have read on