Introduction  

The short hair that grows along the edge of the eyelid is referred to as eyelashes. The lashes are made of sensory hairs which automatically shut the eyelid in case of dust. 

Cosmetically, eyelashes have remained a core part of a human being’s features as the eye’s primary accessory. Lashes renew themselves every six to ten weeks just like an individual’s natural hair. One can lose between one to five lashes daily. In some situations, a more rapid loss of eyelashes occurs, also known as madarosis. Madarosis may be indicative of an underlying health issue in the eye or body in general.

Also Known As

  • Lash
  • Blepharida
  • Cilium
     

Anatomy

There are approximately 75 to 80 eyelashes on the lower eyelid and 90 to 160 lashes on the upper eyelid. Some scientists say that eyelashes measure a third of the width of the eye. These measurements help to keep the eye wet and protect it from dry eye. They are the shortest hairs on the body with the longest life span. Lashes curve among all groups of people.

They have an inner medulla layer composed of cells. The next layer is called cortex or surrounding medulla which gives the lashes its rigidity and strength. The outer layer is called the cuticle, which protects the inner part of the lash since it is not permeable. 

The eyelash follicle comprises of the dermal papilla, the germinal hair matrix around the papilla and the root of the eyelash. The dermis of the eyelid contains the hair follicle. At the base of eyelash follicles lie melanocytes, pigment cells which rarely become cancerous.

Function

Eyelashes play the following significant roles:

  • Assist in blocking out light
  • Prevent irritation of the eye
  • Identify people as well as their eyes
  • Communicate people’s emotions through facial expressions
  • Protect the eye from dust and debris by trapping them before they enter the eye through reflexive blinking
  • Move moisture away from the eye. If sweat and rain come on an individual, eyelashes will channel that unwanted moisture away from the eye. This action helps to keep vision clear. Because of the shape and direction of the eyelashes, the moisture may flow around the eye, along the side of the head and sideways.
     

Associated symptoms & disorders

  • In rare cases, loss of eyelashes could be a symptom of skin cancer on the eyelid. 
  • Trichotillomania can result from stress when a person habitually pulls out their lashes. 
  • From the base of the eyelash, a stye can grow. It is a tiny, red, painful growth caused by a bacterial infection. 
  • Disorders such as alopecia and thyroid disease may cause eyelash loss. Both conditions have the hair falling out from the eyelid, eyebrow or the scalp. 
  • Trichiasis occurs when the eyelashes grow abnormally inwards. Because they rub against certain parts of the eye like the cornea, they end up irritating the eye. 
  • Blepharitis affects people with dry eyes, oily skin and dandruff. It occurs when bacteria and oily pieces settle at the bottom of the lashes. The result is a burning, red and swollen eye. 
  • An unnatural loss of eyelashes is a cause for concern. Lashes may be lost through irritation emanating from cosmetic use. For example, leaving on makeup for too long, mascara allergies or using eye curlers. 
  • Some people tint their eyelashes which experts have termed as being risky. Doctors caution against the cosmetic use of Latisse, a glaucoma medication that lengthens and thickens eyelashes. One irreversible side effect is that the iris and the skin around the eye can darken. 
  • Eyelash extensions are applied by a technician in a beauty salon using tweezers and a semi-permanent glue. The danger comes when the eye suffers from allergic reactions to the glue, trauma or an infection of the cornea or eyelid. The infection can come from inadequate hygiene too. These reactions can lead to temporary loss of eyelashes. Allergies can result in redness, itching, swelling, pain or even interfere with vision. In the course of the application, rubbing, tugging and pulling of the lashes can occur. This action can cause permanent damage to the eyelash follicle. Eyelash extensions can cause fibers to get stuck under the eye tissue necessitating surgical removal. 
  • Other causes for eyelash loss include chronic stress, chronic inflammatory disease, nutritional deficiencies, chemotherapy and hormonal changes such as menopause.
     

Diagnosis of associated disorders

A comprehensive eye examination is needed to identify the specific ailment responsible for eyelash loss. The eye care professional will take a detailed history. He/she may use a special magnifying instrument, for example, to check the eyelid for blepharitis. A swab to collect a sample of skin for testing may also be undertaken. The professional may diagnose a stye by just looking.

Treatment of associated disorders

One needs to maintain skin and eyelash hygiene by washing them with gentle soap and water. Keeping a healthy diet inclusive of proteins, fruits, iron and vegetables is highly recommended. Extra precaution should be taken during makeup application. 

A warm compress, eyelid scrubs, antibiotics and eye drops can treat blepharitis. 

A surgeon may remove the follicle, eyelash or both to treat trichiasis. Alternatively, he/she can redirect the abnormal growth of the lashes. If possible, surgery can eliminate the cancer causing the eyelash loss.

Treating styes with antibiotics, steroid drops, warm compresses and surgery to drain the area can aid the healing process.