Spring time is coming and that spells flower buds, blooming trees — and for the many people who have springtime allergies, it means runny nose, sneezing, congestion, eye irritation, tearing and itching. Seasonal allergies occur during certain times of the year from exposure to certain airborne substances (pollen), particularly the spring, summer, or fall—depending on the particular allergy.   Symptoms usually involve  the membrane lining the nose, causing allergic rhinitis, and  the membrane lining the eyelids and covering the whites of the eyes (conjunctiva), causing allergic conjunctivitis. In the spring, wind-borne pollen from trees such as alder, birch, juniper, oak, maple, elm come across frequently. As Spring finishes and turns to Summer, different types of grasses play a key role, such as orchard, bermuda, timothy, johnson, and weeds such as English plantain and Russian thistle. As Fall comes around, ragweed is the key culprit. Signs and symptoms of a