What are microplastics?
Microplastics are tiny pieces of plastic. Some come from bigger plastic items breaking down, while others are manufactured to be small from the start. They're usually smaller than a sesame seed, and the tiniest ones (called nanoplastics) are so small you need a special microscope to see them.
Microplastics don't go away. They just get smaller and smaller over time. They can come from everyday things like bottles, tires, fabrics and personal care products.
The particles get into the air, water, soil and food, where people can ingest them or breathe them in.
Your eyes are exposed to them too. Studies have found microplastics on and even inside people's eyes.
Why are researchers concerned about microplastics?
Scientists don't have proof yet that microplastics cause specific diseases in humans. But their discoveries are slowly helping them understand how the particles could affect a person's body systems and organs, including their eyes.
Here's what researchers know so far:
- Microplastics are in our bodies – Particles have been found in the blood, brain, heart, gut and other parts of the body. They've also been found on and inside the eyes.
- They can be made of harmful substances – Microplastics can include chemicals like bisphenol-A (BPA) and phthalates (used in plastics like PVC) that disrupt the body's hormone-making endocrine system. These chemicals may also harm other parts of the body.
- They can carry in other chemicals – Microplastics can "pick up" pollutants like per- and polyfluoroalkyl substances (PFAS) and heavy metal molecules and bring them into your body.
- They can stress cells – Studies in labs and animals show that microplastics can cause inflammation and change the way cells behave, which could lead to cancer. But this hasn't been directly proven in people yet.
How microplastics get into your eyes
A layer of tears called the tear film surrounds your eyes and keeps them moist and protected. A healthy tear film traps particles like dust or pollen and flushes them away to limit irritation.
Microplastics can also get caught in your tear film. They might irritate your eyes, but they could also carry harmful chemicals and trigger inflammation.
So far, research suggests that microplastics could get in your eyes in the following ways:
Air
Microplastics in the air (indoors and outdoors) can land on the surface of your eye. They can come from sources such as:
- Clothing with synthetic fibers (like polyester)
- Carpets, rugs and furniture pieces that use synthetic materials
- Tire wear
- Construction sites
- Indoor and outdoor dust (which can carry microplastics)
Contact lenses
Contact lenses are made of plastics like silicone hydrogel. If these materials break down, they could release microplastics into your tear film or other parts of your eyes.
A study in Environmental Science & Technology estimated that a pair of contacts could shed more than 90,000 microplastic particles over the course of a year. But this research was done in a lab and not directly on people's eyes.
While someone's real-world exposure might vary, this study shows why future research is so important.
Eye drops
Microplastics have also been found in widely available eye drop products. The drops could put particles directly on the surface of the eye, which could then move to other parts of the eye and body.
A 2025 study in Environmental Chemistry Letters tested five brands of eye drops and found microplastics in all five samples. However, another 2025 study in the journal Cornea tested three bottles each from 20 different brands (60 bottles total) and only found microplastics in two of them.
Personal care and cosmetic products
Many personal care products contain microplastics or nanoplastics. These particles could get in your eyes when you rinse certain products off your face or scalp. Products can include:
- Shampoos and conditioners
- Soaps and shower gels
- Face washes
- Lotions
- Sunscreens
Microplastics have also been found in eye makeup products such as:
- Mascara
- Eyeliner
- Eye shadow
- Eye glitter
When you use these products around your eyes, it’s possible for stray particles to get into your eyes when you wash them off.
Water
Researchers have found microplastics in tap water and natural bodies of water, such as lakes and rivers.
It's possible that these particles could reach the eye when you're bathing, swimming or washing your face.
Bloodstream or other pathways
Scientists have also found microplastics in people's blood. This means they can travel through the body and might be able to reach the eyes.
In 2024, a study in Science of the Total Environment found microplastics in the jelly-like fluid in center of the eye, called the vitreous humor. Doctors found more than 1,700 microplastics in 49 eye surgery patients.
In 2025, iScience researchers also found microplastics in the aqueous humor. This is the more watery fluid that fills the front part of the eye.
Scientists still don't know how the plastics get into these parts of the eye, so more research is needed.
What microplastics can do to your eyes
Thanks to these studies and one in the Journal of Hazardous Materials, we know that microplastics can enter the tear film and even get inside the eye.
That might sound worrying, and many scientists agree that we should keep studying the ways microplastics affect our eyes. But it's important to remember that the research is still early and there isn't proof that the particles directly cause eye diseases in people.
Here's what studies so far show about effects to different parts of the eyes:
Eye surface
Studies suggest that microplastics can irritate the surface of your eyes and make it less healthy. This could affect both the cornea and conjunctiva, which protect and lubricate the front of your eye.
Cornea
Microplastics may be able to damage the corneal epithelium, the top layer of the cornea (the transparent front surface of the eye).
In one Environmental Pollution study, the cells in this layer absorbed certain microplastic particles. This stressed the cells and made some die off.
Another study showed that microplastics could make the corneal epithelium weaker in animals’ eyes.
Over time, changes like these might hurt the corneas’ ability to protect your eyes. That could lead to more eye injuries and/or infections.
Conjunctiva
The conjunctiva is the thin tissue that covers the white part of your eye and lines the inside of the eyelid.
Goblet cells in the conjunctiva make mucus that helps keep your eye smooth and moist. In animal studies, microplastics led to much fewer and weaker goblet cells.
Changes like these can thin out the tear film, which can cause dry eye-like symptoms and eye inflammation.
Tears
Your tears keep your eyes hydrated and flush out tiny debris and particles.
In animal tests, the eyes made fewer tears when they were exposed to certain microplastics. This got worse the longer the eyes were exposed.
This could potentially cause dry eye disease in humans or make existing symptoms worse.
Meibomian glands
The meibomian glands are tiny ducts along the insides of your eyelids that make the oils in your tear film. These oils help your tears evaporate more slowly so your eyes don't dry out.
Sometimes the glands get blocked or make lower-quality oils, which is a condition called meibomian gland dysfunction (MGD). It's common in people with dry eyes.
Some human cell and animal research shows that microplastics in the meibomian glands can cause eye inflammation that makes MGD worse, but more research is needed.
Pressure inside the eye
If the fluid pressure in your eye (called intraocular pressure) gets too high, it can damage the information pathway to your brain (the optic nerve) and raise your risk for developing glaucoma.
Research has shown that people with high eye pressure often have more microplastics inside their eyes. But it isn't clear whether the microplastics actually cause the higher pressure in some way.
Retina and vision
The retina is the tissue at the back of the eye that sends light signals to your brain so you can see.
Lab and animal studies have shown that microplastics can damage the retina's light-sensing cells and weaken its protective barrier. The term for damage to the retina is retinopathy. It can affect how well the retina works and may lead to vision problems.
Early research shows that people with retinopathy may have more microplastics in their eyes than people without it. But more research is needed to find out if the particles are causing the problem or making it worse.
Scientists don't know exactly what these studies might mean for people, but they offer important information for future research.
What does all of this mean?
We don't know yet. There's evidence that microplastics may not be good for our eyes, but scientists still need more time to find out whether the particles can actually cause eye diseases in humans.
For now, try not to worry too much. Our eyes have probably been exposed to microplastics for a long time, and so far, eye doctors haven't seen an obvious eye health crisis.
You can stay current by checking for new research from time to time and asking your eye doctor for updates during your annual eye exam.
Can you protect your eyes from microplastics?
It's impossible to totally avoid microplastics since they're in the air, water, food and so many other places. But you may be able to lower your eye exposure. For example, you can:
- Wear protective eyewear in situations with lots of dust or debris in the air.
- Wear swimming goggles when you go swimming.
- If you wear contact lenses, practice good contact lens hygiene and don't wear your lenses longer than recommended. You may also consider wearing your glasses more often.
- Consider using an indoor air filter with a HEPA filter. If you have a heating or cooling system that uses replaceable filters, look for filters with a high MERV rating. Both of these options can help catch smaller particles in the air.
- Spend more time indoors and keep windows closed on days when the air quality is poor. You can check the Air Quality Index (AQI) in your area to get more information.
The future of microplastic research
Scientists are still learning how microplastics affect our eyes and overall health. Some important areas of research are:
- Learning more about how microplastics affect the eyes and body.
- Discovering any short- or long-term risks to vision and eye health.
- Helping people make informed choices based on new discoveries.
Microplastics studies are happening all over the world. We might not have all the answers yet, but new research could give current and future generations the information they need to protect their eyes.
