Demodex are microscopic mites — too small to see with the naked eye — that live in and around hair follicles and sebaceous glands across the human body. Two species are found on the face and eyelids:

Demodex folliculorum lives in the eyelash follicles themselves. When present in large numbers it causes the characteristic inflammation and crusting of anterior blepharitis.

Demodex brevis lives deeper in the meibomian glands and sebaceous glands of the eyelid. Infestation with this species is associated with meibomian gland dysfunction and posterior blepharitis.

A small number of Demodex mites is normal and doesn't cause problems. The issue arises when populations grow beyond what the eyelid environment can tolerate — triggering chronic inflammation, disrupting gland function, and creating conditions where bacteria thrive.

How common is it?

More common than most patients — and many clinicians — appreciate. Demodex infestation increases significantly with age. Studies suggest the majority of people over 60 carry Demodex on their eyelids, with a meaningful proportion having infestation levels sufficient to cause symptoms.

It's also underdiagnosed because the signs can be subtle and are easily attributed to other causes. The classic sign — cylindrical dandruff-like debris called collarettes at the base of the eyelashes — is specific to Demodex but requires careful examination to identify.

What are the symptoms?

Demodex blepharitis symptoms overlap with other forms of blepharitis and dry eye disease, which is one reason it's frequently missed:

• Persistent itching of the eyelids — particularly at the lash line
• Redness and irritation along the lid margins
• Crusting or waxy debris at the base of the lashes
• Lashes that clump together or grow irregularly
• A gritty or foreign body sensation
• Burning or stinging eyes
• Eyes that feel worse in the morning
• Symptoms that keep returning despite regular lid hygiene

The itch is often a helpful distinguishing feature — Demodex blepharitis tends to be itchier than other forms of anterior lid disease.

How is Demodex blepharitis diagnosed?

Diagnosis is made through careful slit lamp examination of the eyelid margins and lash bases. The key sign we look for is collarettes — cylindrical, waxy deposits that form a sleeve around the base of individual lashes. These are produced by Demodex activity and are highly specific to infestation.

We also assess:

• The number of lashes affected and the density of collarette formation
• Lid margin redness, thickening, and irregularity
• Meibomian gland function and secretion quality
• Tear film stability
• Any corneal involvement

A thorough assessment distinguishes Demodex-driven disease from other causes and guides the appropriate treatment pathway.

How is Demodex blepharitis treated?

Standard blepharitis treatments — conventional lid wipes and warm compresses — are not effective against Demodex. Targeted treatment is needed.

ZEST — Zocular Eyelid System Treatment ZEST is our primary in-clinic treatment for Demodex blepharitis. It uses an okra-based polysaccharide gel applied to the lid margins with a micro-applicator, providing a deep professional clean that removes collarettes, Demodex debris, and the biofilm that sustains mite populations. It's well-tolerated and produces a significant reduction in mite load and associated inflammation.

Most patients notice an improvement in comfort and lid margin appearance after their first session. A course of treatments produces the best results, followed by a structured home maintenance routine.

LLLT — blue light therapy Blue light at the appropriate wavelength has documented antimicrobial and anti-parasitic properties at the lid margin. Combined red and blue LLLT complements ZEST treatment by continuing to reduce mite populations and associated inflammation between clinic sessions.

Tea tree oil products Terpinen-4-ol, a component of tea tree oil, has activity against Demodex and is found in several specialist lid care products. We'll advise on appropriate formulations for home use — concentration matters, as products intended for skin elsewhere on the body are too strong for use around the eyes.

Home maintenance After in-clinic treatment, a consistent daily lid hygiene routine using appropriate products is essential to prevent reinfestation and maintain results. We'll build a simple, practical routine with you.

The Demodex and dry eye connection

Demodex infestation drives inflammation at the lid margin. That inflammation disrupts meibomian gland function, which destabilises the tear film and causes or worsens dry eye symptoms. The mites themselves may also directly invade meibomian glands, causing further disruption.

Treating the Demodex infestation is therefore not just about eyelid comfort — it's an important part of treating the dry eye disease that frequently accompanies it. We assess and address both as part of the same treatment plan.

Frequently asked questions

How did I get Demodex? Demodex mites are part of the normal human skin flora and are present on virtually everyone to some degree. They're transmitted through close skin contact and shared items like towels and pillowcases. Infestation becomes problematic when populations grow beyond normal levels — this is more likely with age, compromised immune function, and certain skin conditions including rosacea.

Is it contagious? Demodex can be transmitted between people through close contact. If you're being treated for significant Demodex blepharitis, it's sensible for people you share a bed or towels with to be aware — though routine social contact carries negligible risk.

Can I treat it myself at home? Home products can help maintain results and slow reinfestation, but they're not sufficient to treat established Demodex blepharitis on their own. In-clinic treatment provides a level of deep cleaning that home care cannot replicate.

Will it come back? Demodex is part of the skin's normal environment, so complete eradication isn't the goal — reducing the population to a level that doesn't cause disease is. With appropriate treatment and ongoing maintenance, most patients achieve good long-term control. Some patients need periodic top-up treatment.

Do I need a referral? No. You can book directly with us for a dry eye and eyelid assessment.

Stop managing the symptoms — find out what's actually causing them

If your eyelids have been persistently uncomfortable despite your best efforts with lid hygiene, it's worth finding out whether Demodex is involved. A proper assessment will give you a clear answer.

📍 Openshaw Opticians, Unit 4, 16 Cheapside, Cleckheaton, BD19 5AF 

📞 01274 878214