Conjunctivitis is a minor eye infection that causes an inflammation of the conjunctiva (the thin layer of tissue that covers the front of the eye). The condition is very common and is often referred to as red eye. Conjunctivitis can cause the eye(s) to feel itchy, watery and in some cases can produce a sticky/crusty coating at the base of the eyelashes. Conjunctivitis will usually affect one eye, however, it can spread to both eyes after a couple of hours.
Conjunctivitis can be caused by a variety of factors. If the conjunctiva has become inflamed as a result of a bacterial or viral infection, this is referred to as ‘infected conjunctivitis’. The condition can also be caused by an allergic reaction to a substance like pollen and dust mites. This form of conjunctivitis is called ‘allergic conjunctivitis’. If the condition has been brought on as a result of the eye coming into contact with an irritant, this is known as ‘irritant conjunctivitis’. Substances that can irritate the conjunctiva include; loose eyelashes, soaps and shampoos, chlorinated water.
Treatment isn’t always necessary for conjunctivitis, the symptoms will typically clear within two weeks. If treatment is needed, the choice of medicine will depend on the cause of the irritation. In severe cases of infected conjunctivitis, an antibiotic eye drop is available to help clear the infection.
Blepharitis is a common eye condition that affects the edges of the eyelids, causing them to become inflamed or swollen. For the majority of cases, both eyelids are affected. However, for many sufferers, one eye tends to be more severely affected than the other. Blepharitis can be divided into three categories:
- Anterior blepharitis – affects the skin that surrounds the base of the eyelashes. Anterior blepharitis is usually caused by a bacteria called Staphylococcus. This bacteria can live harmlessly on a person’s skin. However, for some people they can cause inflammation of the eyelids. Anterior blepharitis can also be the result of seborrheic dermatitis, which is a common condition that results in the skin becoming oily or flaky. This can irritate the eyelids, causing them to become inflamed.
- Posterior blepharitis – affects the Meibomian gland, which is found along the eyelid margins. This form of blepharitis is typically caused by a problem with the Meibomian glands, where they can become blocked by excess oil, debris or skin flakes. This can result in inflammation.
- Mixed blepharitis – this type is a mixture of both anterior and posterior blepharitis.
Blepharitis is typically a long-term condition. Most sufferers will experience repeated episodes, which are separated by symptomless periods. Although the condition cannot be cured, it is possible to successfully manage the symptoms by adopting a daily eyelid cleaning routine.
In most cases, blepharitis isn’t serious, although it can potentially lead to further problems, such as dry eye syndrome. In more severe cases of blepharitis, antibiotics may be required to control the symptoms.
Styes are small, painful lumps that can develop on the inside or outside of the eyelid. Also known as Hordeolums, there are two different types of stye:
- External hordeolum: These are swellings that occur along the edge of the eyelid. They may develop into a yellow pus-filled spot that is painful when touched.
- Internal hordeolum: These styes develop inside of the eyelid. These swellings are generally more painful than an external stye.
Styes, like blepharitis, are often caused by an infection from staphylococcus bacteria. Styes are often linked with the condition blepharitis, and in many cases can be an associated symptom. Other factors that can lead to a stye developing include:
- An eyelash follicle infection (external stye): These are small holes of the skin where eyelashes grow out from.
- An infection of the sebaceous gland (external stye): This gland produces sebum and is attached to the eyelash follicle.
- An infection of the apocrine gland (external stye): This is a sweat gland that covers the eye with tear film to prevent the eye from drying out.
- An infection of the Meibomian gland (internal stye): These glands are located on the eyelids and produce an oily substance, which constitutes part of the tear film that lubricates the eye.