Most cases of itchy eyes are caused by an allergy. The allergy could be caused by animal dander or saliva, or dust mites, or by a seasonal allergy.
The term “seasonal allergy” refers to the body’s allergic reactions to grass, pollen, and mold, but can also include other allergies associated with the spring/summer/fall seasons such as smoke from campfires and chlorine in swimming pools.
Whatever the trigger, if you suffer from allergies, seasonal or other, then itchy, red, puffy, light-sensitive eyes can be one of its irritating consequences.
The cause of itchy eyes from allergies is our immune system's exaggerated response to a "harmless" allergen trigger as though it were an invading bacteria or virus.
Our immune system works to keep us healthy by attacking foreign germs (bacteria and viruses) before infecting us. Our immune system is very complicated, but keeps us healthy at many levels or in many different ways. Our immune system can coordinate an army of cells to mount attack against other cells or foreign "antigens."
In the case of seasonal allergies, "harmless" allergens (pollen, dust, dander) still trigger a different type of immune response. Though harmless, in those of us "allergic" to these particles, a chain reaction results in our body releasing histamine in response to the triggers.
Histamine mediates an inflammatory response to help your body protect itself from these foreign agents. A side effect of histamine is itchy, runny eyes and noses.
Strategies and Treatments
Avoiding allergens eliminates the problem before it starts. If you know your allergen trigger you can take steps to avoid it such as staying indoors and using air conditioning for air filtration when pollen counts are high. Wraparound sunglasses will also minimize eye contact with allergens present in the outdoor air.
Don’t rub your eyes because that releases more histamine and makes your symptoms worse and could cause a corneal abrasion.
A warm, moist washcloth placed over your closed eyes will help soothe the severity of itchy eyes.
Over-the-counter eye drops formulated to relieve itchiness caused by allergies may work to relieve your symptoms if your allergy is not severe.
Prescription eye drops and oral medications are options for relieving severe allergic eye symptoms.
Discontinue contact lens wear until your eye allergy symptoms have subsided. Contacts can absorb allergens and keep those allergens in contact with your eyes, so consider switching to glasses during allergy season.
Itchy, red eyes aren’t only caused by allergies. Blepharitis (inflamed eyelids) caused by bacteria, dry eye syndrome, and meibomian gland dysfunction can all cause itchy eyes or make sufferers more susceptible to itchy eyes.
Only your doctor will be able to determine the cause of your itchy eyes and which treatment or combination of treatments will work for you. For example, if the cause or your itchy eyes is blepharitis then you may get relief by using an eyelid cleanser, and if the cause is dry eye syndrome then other treatment methods that address tear quality and evaporation will be needed to treat your itchy eyes.