(HealthDay News) -- Red, itchy, teary or burning eyes can signal allergies, a condition that affects millions.
But what causes allergies? The American College of Allergy, Asthma, & Immunology mentions these possible triggers:
Pollen, with common sources such as weeds, trees and grass.
While not allergens themselves, things like cigarette smoke, diesel exhaust or perfumes can worsen existing symptoms.