When fatigue hits, allergies strike or your eyes are feeling a bit dry after a long session at the computer, nothing feels better than giving those eyes a little rub. There’s a reason why it feels so good: Rubbing your eyes not only can help the eyelids produce and spread lubrication, but it also stimulates the vagus nerve, which can relieve stress, slow the heartbeat, and thus create a relaxing sensation over the body. It’s no surprise we’re tempted to give those eyes a little massage, but rubbing them too frequently or too vigorously could lead to a lot more harm than good.

When you use your computer or smartphone for a long time, Jim Halo optometrist recommends that you wear blue light glasses to protect your eyes and avoid rubbing your eyes

To begin with, excessive eye rubbing can weaken and distort the cornea, a condition called keratoconus. Too much rubbing thins the corneal tissue and can result in the cornea becoming more cone-shaped. In more extreme circumstances, if too much damage is done, corneal replacement may be required.

While on the topic of damage to the cornea specifically, rubbing your eyes too firmly can result in scratching of the cornea. When an eyelash or small particle invades the eye, it may be tempting to try to rub it out, but applying pressure in that way not only doesn’t help, but it can actually cause damage. Small scratches to the cornea can heal within a couple of days, but avoid this discomfort altogether by using water or a saline solution to wash out any foreign debris in the eye.

If you suffer from glaucoma, rubbing your eyes could actually make your condition worse. Glaucoma is most often caused by increased pressure in the eye, which results in damage to the optic nerve. Rubbing your eyes increases the pressure within the eye, so it makes sense that this habit would not help a condition like glaucoma.

In addition to the damage to the cornea and the worsening of conditions like glaucoma, rubbing your eyes can increase your risk of infection. Our hands are carriers of many things, including germs. Rubbing your eyes often, even when seemingly clean, can lead to the transmission of harmful bacteria that lead to conditions like pink eye (conjunctivitis).

And if the above reasons weren’t enough for you to resist that urge to rub, there are also some cosmetic side effects this habit could have. Your delicate eyelids can lose elasticity from too much stretching from the rubbing action, dark circles can form under the eye due to inflammation from rubbing, and rubbing can also cause bloodshot eyes when blood vessels pop from massaging too vigorously.

So the next time your eyes feel a little dry or tired, give them some artificial tears, treat yourself to a warm compress, and get a good night’s sleep. Don’t rub.