In many cases itchy eyes are a symptom of allergic conjunctivitis or allergies. Allergic conjunctivitis is a very common condition . It can develop at any age. When people have listened the term “allergy”, then they expect to sneeze. But our noses are not the only part of our bodies that can have allergy. Our eyes can also have allergies. But it is more common condition in adults compared with children. This condition can be chronic or acute. You may develop additional symptoms that are depending of variety such as blurred vision or a swollen eyelid. If you are diagnosed with eye allergy, then you should know the real cause for this condition because it can develop with age as other types of allergies.
Causes for itchy eyes
Like all other allergies, we can get eye allergy when our bodies are overreacting to something. Our immune system makes antibodies that are causing our eyes to release histamine and other substances. This is a reason why we have watery, red and itchy eyes. Also there are some people who get nasal allergies.
Types of eye allergies: There are two types of allergic conjunctivitis:
- Perennial allergic conjunctivitis: This type of allergic conjunctivitis happens all year long due to constant exposure to household allergens such as pet dander, dust and mold. 
- Seasonal allergic conjunctivitis: This type of allergic conjunctivitis typically happens during fall and spring in which periods we are exposed to allergens such as weeds, pollen and grass. 
But also if we have itchy eyes, then this condition can be caused by diseases such as blepharitis and dry eye. If you have noticed that you have itchy eyes and you know that you do not suffer from any kind of allergy, then you should talk with your doctor as soon as possible because he or she will check your health to discover if you have any underlying condition.
What other problems do itchy eyes cause?
During our allergic reaction we can have additional symptoms such as
- Sneezing or runny nose
- Congestion, wheezing, difficulty breathing
- Inability to open eye due to swelling
- Difficulty seeing or blurred vision
- Swollen eyelid
- Red bloodshot eyes
- Watery eyes
People are often asking why they get itchy eyes?
When the surface of our eyes is exposed to allergens, then is happening an allergic reaction. The reaction triggers the release of histamines causing watery, red and itchy eyes. You should not rub your eyes. If you rub your eyes more and more, then you are releasing more and more histamines which can result in worse symptoms. If you are rubbing your itch, then you can cause scratch or another trauma to the surface of your eyes. Many eye conditions can be a reason for itchy eyes. If you have dry eyes, then they can cause you irritation and discomfort. 
Blepharitis which is not a contagious eye disease can be caused by skin or bacterial conditions which can also lead to itchy eyes. When we have blepharitis, then our eyes become itchy, scaly and dry. In this condition in the most cases our eyelashes are falling out. In some cases our eyelashes can grow back abnormally which is a condition that is known as trichiasis. This condition can cause irritation to our eyeball. There are some people who are allergic to their contact lens solution which is causing them inflammation, itching, discomfort and redness. [4,5]
Thimerosal is a preservative which is found in many contact lens solutions and it is used in ophthalmic products is one of the biggest causes why we have allergic reactions to our contact lens solutions. You should stay indoors when the pollen counts is at the highest level which is usually in the early evening and the mid – morning. You should close your windows and also you should run the air conditioner. It is known fact that the window fans can draw the mold and pollen spores. When you are going out, then you should wear big sunglasses or eyeglasses because in this way you will block the pollen from your eyes. When you are driving your car, then you should close your windows and you should let run the air conditioner to avoid itchy eyes. 
 American College of Allergy, Asthma & Immunology. Eye allergy. Retrieved from acaai.org/allergies/types/eye-allergy
 La Rosa M, Lionetti E, Reibaldi M, et al. Allergic conjunctivitis: a comprehensive review of the literature. Italian Journal of Pediatrics. 2013;39.
 Ackerman S, Smith LM, Gomes PJ. Ocular itch associated with allergic conjunctivitis: latest evidence and clinical management. Therapeutic Advances in Chronic Disease. 2016;7(1):52–67.
 Putnam CM. Diagnosis and management of blepharitis: an optometrist’s perspective. Clinical Optometry. 2016;8:71–8.
 Urgacz A, Mrukwa E, Gawlik R. Adverse events in allergy sufferers wearing contact lenses. Advances in Dermatology and Alergollogy. 2015;32(3):204–9.