To put it simply…. Eye rubbing is dangerous, and detrimental to our health. Eye rubbing may seem like an innocuous gesture or habit, but it can cost us our vision.
THE DANGERS OF EYE RUBBING
How rubbing affects the eye depends on the intensity of the ocular friction, the frequency, the age at which eye rubbing first started and the status of the underlying cornea. If we rub vigorously, repetitively, over prolonged periods, from a young age and if our cornea is thin to start with, the risk of weakening and further thinning of the cornea is very high.
Rubbing can cause tiny scratches on the surface of the eye. If there are foreign particles like flecks of dust or makeup on the surface, rubbing the eyes vigorously may result in a bigger scratch on the surface, and this is termed a corneal abrasion. Abrasions are painful and can cause scarring of the cornea. If this scar is located centrally, it can cause permanent damage to vision. Abrasions can also become infected, leading to cornea ulcers and abscesses, which require emergency medical treatment with antibiotics.
Well documented in this website and in many medical studies, chronic and aggressive eye rubbing can lead to a thinning of the cornea that in turn can lead to keratoconus (See What is Keratoconus). In patients who have had refractive surgery, such eye rubbing habits can weaken the cornea and lead to corneal ectasia. Keratoconus and corneal ectasia result in a deterioration of vision that often cannot be reversed or fully corrected with glasses or contact lenses. Eye-rubbing is not only responsible for the onset of these conditons but also hastens the progression of the disease.
Our hands carry the most germs in any part of our body, and eye rubbing introduces these germs directly onto the surface of the eye. Not only are germs (like bacteria, fungus, parasites and viruses) spread in this manner, substances that can potentially cause allergies (allergens) are also introduced into the eye. The eyelids and eye lashes protect the eyes to a certain extent from these germs and allergens, but in many instances, infection or inflammation of the ocular surface (conjunctivitis) results. Conjunctivitis causes the eye to turn pink or red and teary. We should always practise proper eye hygiene by washing our hands before touching our eyes, inserting contact lenses or applying eye make-up. The best thing however is to keep our hands away from our eyes, and avoid rubbing them altogether.
We sometimes rub our eyes because of itch. If the itch is caused by allergies, rubbing can release chemicals called histamines into the area around the eyes, inducing more itch and starting a « itch-rub-itch » vicious cycle. As described above, rubbing with dirty hands spreads germs & allergens, creates an inflammatory reaction in the eyes, and releases histamines and proteolytic enzymes into the tear film. Eye rubbing has been also shown to cause an increase in the levels of interleukin-6 (IL-6), tumor necrosis factor-α(TNF-α), and matrix metalloproteinase (MMP)-9 in the tears. Not surprisingly, in the tears of patients with keratoconus, where eye rubbing is likely the root cause, increased levels of MMP-13, IL-6, and TNF-α have also been found. These substances are responsible for the inflammation induced by eye rubbing.
Some people with diseases such as glaucoma (nerve damage due to eye pressure), keratoconus and progressive myopia (rapidly increasing shortsightedness) are possibly at risk of worsening of their condition if they are frequently engaged in activities that raise their eye (intraocular) pressure.
Eye rubbing tends to cause a spike in the intraocular pressure, but this is harmless if this spike does not last longer than a few seconds. However, for those who rub their eyes vigorously and incessantly with rubbing episodes lasting for minutes and continuing over many years, the eyes are biomechanically stretched and stressed, and this can result in the worsening or progession of the disease conditions mentioned above.
Rubbing your eyes can cause blood vessels on the surface of the eye (conjunctival blood vessels) to rupture, leaving your eyes bloodshot. This is called a subconjunctival hemorrhage. It is visually innocuous but cosmetically unacceptable to many. Depending on the extent, subconjunctival hemorrhage usually takes 5-10 days to clear spontaneously
Eye rubbing not only affects the surface of the eye and the cornea, it also affects the eyelids. Problems induced by chronic and vigorous eye rubbing include droopy eyelids, dark under eye circles, wrinkles and lines. Many of these issues have to be surgically corrected.