A Sight For Sore Eyes

Have you ever experienced itchy, watery eyes as a result of seasonal allergies? The objects in this picture are to blame. This microscope image shows conjunctival tissue from an eye in the presence of a single mast cell. Mast cells are important regulators of the immune system. Upon invasion of the eye with foreign objects, such as allergens, the mast cell is recruited to the tissue and releases histamines (shown in this picture as red vesicles) into the surrounding tissue, eliciting an inflammatory response. The collagen fibers in the eye (pink) then separate and a cascade of events occur that result in red, watery, itchy eyes.

Artist: Don Pottle. Author: Rebecca Clements.