October 10, 20256 min ReadLast reviewed November 28, 2025

Blepharitis Causes & Risk Factors: Why Me?

Blepharitis is rarely caused by 'poor hygiene'. We explore the biological factors—from bacteria to skin conditions—that drive eyelid inflammation.

Macro texture of eyelid skin suggesting oil gland structure.
D
Dr Awais Rauf
Ophthalmologist, CCT (Ophth) UK
Reviewed by Dr Awais Rauf
Medically Reviewed

One of the most common misconceptions about blepharitis is that it results from being unclean. This is false. Blepharitis is a complex inflammatory condition often linked to your skin type, the natural bacteria living on your body, and your environment.

"Understanding the root cause is the first step to tailoring a treatment that actually works, rather than just treating the symptoms."

The Bacterial Overload

Everyone has bacteria on their skin. However, people with blepharitis often have an overgrowth of Staphylococcus bacteria near the base of the eyelashes.

These bacteria produce exotoxins that irritate the eyelid surface. Over time, your immune system reacts to these toxins, causing the redness, swelling, and crusting characteristic of the condition. It is an inflammatory cycle: the bacteria irritate the eye, the eye gets inflamed, and the inflammation creates a better environment for bacteria to thrive.

The Demodex Mite Factor

Demodex mites are microscopic parasites that live in hair follicles and oil glands. They are a normal part of the human microbiome and are found on almost all adults.

Microscopic-style view of Demodex mites in an eyelash follicle.
Demodex mites inhabiting an eyelash follicle.

In some individuals, the population of these mites explodes. Demodex folliculorum bury themselves head-first into the lash follicle, feeding on dead skin cells. Their waste products and the debris they create (cylindrical dandruff) cause significant inflammation. This type of blepharitis is often resistant to standard antibiotics and requires tea tree oil or specific anti-parasitic treatments.

Associated Skin Conditions

Your eyelids are simply a continuation of the skin on your face. Therefore, generalized skin conditions often manifest as blepharitis.

1. Ocular Rosacea

If you have rosacea (facial redness, flushing, broken blood vessels), you are at a very high risk for blepharitis. In fact, up to 50% of rosacea patients have ocular involvement. The inflammation affects the oil glands (Meibomian glands), leading to posterior blepharitis.

2. Seborrheic Dermatitis

This condition causes dandruff on the scalp and eyebrows. When these greasy scales fall onto the eyelashes, they irritate the eye surface.

Risk Factors Checklist

Certain lifestyle and biological factors can predispose you to chronic flares:

  • Age: Incidence increases as we age due to decreased tear production and hormonal changes.
  • Hormones: Androgens regulate oil production. Menopause or hormone replacement therapy can alter the oil composition, leading to dry eye and blepharitis.
  • Contact Lenses: Long-term wear can harbor bacteria and disrupt the natural tear film.
  • Cosmetics: Heavily applied eyeliner can block the gland openings (orifices) on the eyelid margin.

Blepharitis flare-up triggers

Even when the underlying cause is stable, flare-ups can be triggered by everyday factors. These do not cause blepharitis on their own, but they can worsen symptoms.

  • Dry environments: Air conditioning, heating, and wind accelerate tear evaporation.
  • Prolonged screen time: Reduced blinking leads to gland blockage and irritation.
  • Cosmetics and lash products: Makeup residue and removers can inflame the lid margin.
  • Contact lenses: Extended wear can increase irritation during flares.
  • Skin flares: Rosacea or seborrheic dermatitis can trigger eyelid inflammation.

Related content

FAQs

What causes blepharitis in adults?

It is usually multifactorial, involving bacteria, skin conditions, meibomian gland dysfunction, and sometimes Demodex mites.

Is blepharitis caused by poor hygiene?

No. It is an inflammatory condition linked to biology and skin health, not simple cleanliness.

Is blepharitis linked to rosacea?

Yes. Ocular rosacea is a common trigger for posterior blepharitis.

Can Demodex mites cause blepharitis?

Yes. Overgrowth of Demodex mites can inflame the lid margin and cause collarettes.

Why does blepharitis keep coming back?

It is chronic and flares when oil glands clog or inflammation builds up, so ongoing maintenance is often needed.

Scientific References

  1. Jackson WB. Blepharitis: current strategies for diagnosis and management. Can J Ophthalmol. 2008.
  2. Liu J, et al. Pathogenic role of Demodex mites in blepharitis. Curr Opin Allergy Clin Immunol. 2010.