When someone has an allergy to tree pollen, irritation of the eyes can occur. The pollination season of different trees varies, which makes the allergy season long, extending from spring to the autumn.
When tree pollen is in the air, allergic people will exhibit itchy, swollen, watery and burning eyes. Generally both eyes are affected at the same time, but in some instances, one eye may have symptoms while the other does not.
The tissue surrounding the eye, the conjunctiva, has many mast cells that are part of the immune system. These mast cells trigger the release of histamine to counteract foreign substances like tree pollen, causing an allergic response in the eyes.
Some trees produce more pollen than others, causing the strongest eye irritation during the time they pollinate. A few of these trees are hickory, oak, box elder and elm.
There are some relatively effective measures to take to prevent eye irritation due to tree pollen. Stay inside during periods of high pollen count, avoid heavily wooded areas, or try a specialised filter system known as HEPA (high efficiency particulate air).
Over-the-counter antihistamines are available to treat symptoms, but if eye irritation does not respond, a stronger medicine might be needed. An allergist can provide a stronger prescription of eye drops or medication containing antihistamine.