Blepharitis: why the eyelids become inflamed and how it is treated

The edge of the eyelid is a strip only a few millimetres wide, but it is very crowded. The lashes grow there, a row of small glands that produce the oily part of the tears opens there, and bacteria live there and, in many people, tiny mites. When this balance breaks down, the edge becomes red, thickens and gets covered in crusts: this is blepharitis.

People who have it are looking above all for blepharitis treatments that work, and often try many. Systematic reviews tell a less simple story than many products promise: some measures give relief, but no treatment has so far had solid evidence of resolving the chronic form¹.

In this article

1. What blepharitis is: anterior and posterior
2. The meibomian glands and the link with dry eye
3. Demodex: the mites of the lashes
4. Blepharitis: remedies put to the test of the studies
5. Frequently asked questions
6. Sources

What blepharitis is: anterior and posterior

Studies distinguish two main forms, which often coexist¹:

• anterior blepharitis, which affects the outer part of the edge, where the lashes grow; it can be linked to bacteria such as staphylococci or be seborrhoeic in type^1,7;
• posterior blepharitis, which concerns the meibomian glands, the glands of the inner edge that produce the oil of the tears; specialists also call it meibomian gland dysfunction¹.

Typical complaints are redness, a feeling of dryness, discomfort, a foreign-body sensation, itching and abnormalities of the lashes⁵. It is often a chronic condition, which comes and goes: for this reason reviews speak of chronic blepharitis¹.

The meibomian glands and the link with dry eye

Malfunction of the meibomian glands is not a rare problem. A 2021 meta-analysis estimated that malfunction of these glands affects about 36% of the people examined, with very different values between populations: from 21–30% in people of African and Caucasian ancestry up to 68–71% in Hispanic and Arab populations. Men were slightly more affected than women. The authors warn that the studies differed greatly in quality, age and diagnostic criteria².

Blepharitis and Demodex mites appear among the eye-related risk factors for dry eye¹⁰. For this reason the two conditions often go together, and anyone with blepharitis has good reason to read our article on the symptoms of dry eye as well.

Demodex: the mites of the lashes

Demodex are microscopic mites that normally live in the sebaceous glands of the skin; they usually live alongside us without causing problems, but in certain conditions they can become harmful. A 2025 meta-analysis estimates their presence in about 35% of people in the world, with higher values over the age of 60 (59%) and in patients at eye clinics (57%); on the lashes the frequency was 33%. The authors, however, report large differences between studies and signs of publication bias³.

The link with blepharitis is robust. A meta-analysis of case-control studies on 4,741 people, 2,098 with blepharitis and 2,643 without, found a likelihood of infestation about five times higher in those who had blepharitis (odds ratio 4.9)⁴. Studies of this type show an association; on their own they do not say whether it is the mites that cause the problem.

According to a 2023 review, the mites can damage the edge in several ways: mechanically, by carrying bacteria and by triggering hypersensitivity reactions and inflammation. The typical sign is the sleeve-like crusts that wrap around the base of the lashes. The risk factors for Demodex blepharitis are age, rosacea, a skin disease of the face, and diabetes⁵.

Blepharitis: remedies put to the test of the studies

The 2012 Cochrane review on chronic blepharitis pooled 34 studies with 2,169 people: 1,661 with anterior or mixed blepharitis and 508 with posterior blepharitis. The studies were so different that only rarely could they be combined. The main results¹:

• eyelid hygiene can give relief from symptoms, in both the anterior and the posterior form;
• topical antibiotics gave some relief in the anterior form and reduced the bacteria on the edge;
• for topical corticosteroids and oral antibiotics the results were inconclusive.

The authors’ conclusion is clear: no treatment has solid evidence of resolving chronic blepharitis, and many commercial products are sold without substantial evidence of effectiveness. The authors ask that new treatments be compared with traditional measures, such as warm compresses and washing the edge of the eyelid¹.

Oral antibiotics were examined in a 2021 Cochrane review, which found only two randomised trials with 220 people, treated with doxycycline or with a placebo for one or three months. The evidence on the effect on symptoms was judged to be of very low certainty⁷.

Tea tree oil, widely used against Demodex, was assessed by another Cochrane review, from 2020: six randomised trials with 562 people, all with a risk of bias that was not low. The effect on reducing mites after four to six weeks is uncertain, and three studies found no differences in symptoms compared with other treatments⁸.

More promising are the results of an anti-parasitic eye drop, lotilaner, in the phase 3 Saturn-2 trial. In 21 US centres, 412 people with Demodex blepharitis received for six weeks either the eye drop or the same liquid without the active ingredient. At the end, the crusts had disappeared in 56 people out of 100 in the first group and in 12–13 out of 100 in the second; the mites had been eliminated in 52% against 15%. The trial lasted six weeks: it does not say how long the results last over time⁹.

The starting point remains the examination: it is the ophthalmologist who distinguishes the anterior form from the posterior one, looks for Demodex and chooses among the options. Treatments for the dry eye that often accompanies blepharitis are described in our article on remedies for dry eye.

Frequently asked questions

Does blepharitis go away on its own?

It is often chronic and comes and goes. The Cochrane review found no solid evidence that any treatment resolves it in a lasting way; eyelid hygiene can, however, give relief from symptoms¹.

What are the crusts at the base of the lashes?

In Demodex blepharitis, sleeve-like crusts appear that wrap around the base of the lashes: according to a 2023 review they are the typical sign of this form⁵. It is the ophthalmologist who recognises them and distinguishes them from other causes.

Do warm compresses help against blepharitis?

A review of 22 studies found that warm towels reduce symptoms, but they cool quickly and lose effectiveness if they are not reheated⁶. Cochrane lists them among the traditional measures against which new treatments should be compared¹.

Does tea tree oil work against Demodex?

The evidence is uncertain: in six randomised trials with 562 people it is not clear how much it reduces the mites, and symptoms did not improve more than with other treatments⁸.

Blepharitis is rarely serious, but it is stubborn. The studies point to simple measures as the starting point, such as hygiene and warmth on the eyelids^1,6, and urge caution towards easy promises: for many products the evidence of effectiveness is still thin¹.