(NewsUSA) - Fifty million Americans suffer from allergies at some time during the year. A significant percentage of those who are susceptible to allergens experience most of their symptoms in their eyes.

Allergic conjunctivitis happens when irritants like mold, pollen or dust enter the eye and inflame the inside of the eyelid. Eyes may feel gritty, itchy, watery or swollen. Some people report temporarily blurred vision.

For contact lens wearers, allergies can prove especially problematic. Contact lenses can collect and trap irritants on the eye, aggravating allergy symptoms and sometimes causing infections. Many people choose to wear glasses during allergy season. But Americans with year-long allergies find little relief -- some allergen-sensitive people cannot tolerate contact lenses.

Prescription eyedrops, pills or allergy therapy can help reduce symptoms, and some companies are working to make contact lenses healthier for allergy sufferers. Wearers can throw out daily disposable contacts to avoid allergen build-up in eyes, too, but that can be very expensive.

Here are some tips for people with allergies who wear contact lenses during allergy season:

- If your eyes become itchy while wearing your contacts, do not rub your eyes, which can damage tissue. Gently dab moisture away with a tissue, and then remove your contacts as soon as possible. Always keep an extra pair of glasses on hand.

- Reduce the allergens in your life. Do not wear eye makeup unless formulated for sensitive eyes. Wash your sheets and pillowcases in hot water at least once weekly. Keep rooms vacuumed and dusted.

- If redness lasts more than a few days, or if you notice swelling or discharge, see an eye doctor immediately.