Dry eye is another cause of ocular itchiness. Regardless of the cause rubbing your eyes will not improve the underlying condition. You may make your eyes temporarily feel better for a few seconds but the rubbing can eventually lead to some potentially serious ocular conditions.
Ocular infection
Obviously no one scrubs down prior to rubbing their eyes. When you place your fingers in your eyes you are potentially introducing germs and microbes which increase your risk of developing an eye infection. You're particularly prone to developing an eye infection when you rub your eye vigorously and break the corneal epithelium allowing germs to be introduced through the ocular surface.
Dark circles under the eyes
Rubbing your eyes can lead to a rupture of the small blood vessels in the superficial eyelid skin. This rupturing and subsequent deposition of a pigment called melanin can lead to the development of those dark circles that you will see under your eyes.
Foreign Bodies
if there is a foreign body embedded in your ocular surface, then rubbing your eyes may cause it to dislodge and scratch and abrade the ocular surface. Even worse, you might cause it to penetrate the eye.
Keratoconus
There is an eye disease called keratoconus which can be induced by eye rubbing. This is a condition which also has a genetic component where ongoing rubbing of the eyes causes the collagen in the cornea to break down. This leads to the front window of the eye known as the cornea, to thin and become pointy and develop irregular astigmatism with very blurred vision.
Allergies
Rubbing your eyes causes the mast cells in the eyelid to rupture and break releasing histamine. This histamine results in even more itchiness leading to a vicious cycle of rubbing and itchiness.
Floppy eyelids
it is thought that chronic eye rubbing in some people can lead permanent structural changes in your eyelids leading to the lids becoming thinner and floppier.
Contact lenses
Protein or mucous deposits on lenses will cause the lens to dry, leading to ocular irritation and itchiness.
So what can you do if you suffer itchy eyes and are tempted to rub? The first thing is to determine the cause of the itchiness. If you have been grinding or welding the first thing to exclude is an ocular foreign body. The best web determining this is to see your optometrist who will examine your eye under a microscope called a streetlamp. If you find the rise are more itchy in spring and summer and you suffer from asthma, sinus, rhinitis and general allergies then it is more likely that you are suffering from an ocular allergy. This needs to be treated with the appropriate antihistamine eyedrops such as Patanol or Zaditen drops twice daily. If your eyes are more itchy when you are in air-conditioning and towards the end of the day it is more likely that you're suffering from dry eye and a lubricant eyedrop can be used such as Systane, Optive or Refresh.
