The cornea, the front of your eye, is the only area of your body that receives oxygen directly from the air. One reason contact lens wearers are predisposed to dry eyes is because the contact lens on your cornea can partially block oxygen from entering the eye. Although many contact lenses are designed to allow larger amounts of oxygen to permeate the eye, wearers can still experience dry, gritty eyes, especially towards the end of the day.
Another cause of contact lens-induced dry eye is the lenses’ absorption of tears. Lenses need liquid to stay soft and maintain their shape and integrity.
This is known as contact lens-induced dry eye.
In a healthy eye, tears allow the contact lens to comfortably swim in the tear film above the cornea. A shortage of lacrimal fluid can lead to gaps in the tear film, causing the contact lens to irritate the surface of the eye. That, in turn, causes pain, redness and itchiness.
This effect can be further exacerbated if the lenses are low in quality or are poorly fitted to the eye. Such contacts absorb too much liquid from the tear film, causing the eye to lose vital moisture. This can also occur when traditional soft lenses are worn for an extended period of time.