Do we get eye allergies by something we are exposed to like dust,pollen,etc or by something we eat or touch?

Basics: You don't "catch" allergies from another person. They are a personal response to any factor that the body develops an allergic response to. Many inherit the tendency toward immune response that may express itself in many ways. Many also confuse a natural irritant response to dust or airborne pollen with allergies. Eye irritation/allergy is driven by contact with the triggering factor.