We all rub our eyes in different ways. Sometimes it is with one finger, other times with the palms of both hands, the fists or with the knuckles and pulps of the fingers.
HOW DO WE RUB OUR EYES?
Rubbing the eyes with the finger pulps is the less aggressive way for the cornea, but when it done repeatedly and in a circular way, it can cause progressive thinning of the cornea, and the apparition of mild vertical asymmetry on corneal axial curvature topography maps. Similar horizontal movements are usually performed to remove eye make-up.
Patients who rub their eyes with the nails tell us that it relieves the eye itch quickly. But it remains dangerous because the contact with the cornea is traumatic with this hard part of finger. It may even be responsible for corneal abrasions.
Rubbing with the knuckles, which are the hardest parts of the hands, is most deleterious to the cornea, and has the highest risk of inducing keratoconus. The most severe corneal deformations are observed with this type of rubbing. The index knuckles are mostly used to rub, followed by the thumbs knuckles.
Rubbing your eyes with your thumb(s) causes significant pressure on the eyes, providing a feeling of well-being by activating the vagal reflex.
Patients rubbing their eyes with the thumb often do it with one hand, with the index finger rubbing the contralateral eye. In such situation, the most affected eye corresponds to the eye rubbed by the thumb (i.e the right eye when the right hand is used).
Friction with the palm of the hand is often underestimated, many of our patients rub their eyes in this way by performing a circular motion and a strong compression on the eye, which often gives them a feeling of well-being too (same mechanism as thumb compression). Some patient claim that this kind of friction can attenuate headaches. Some patients use the palm of the hand to hold their head, resting on the elbow. The palm of the hand can rest on one orbit, causing local compression and subsequent inflammation and local contamination.
Rubbing with the fists is particularly dangerous and creating an important biomechanical stress on the cornea, the force caused is considerable on the scale of the cornea. The fists are hard, and like for the knuckles, they can cause severe corneal distortion.