The goal of this page is to offer a historical review of literature on pollen sensitivity and ocular allergy, with a focus on advances in the last 5 years. Pollen research is now being conducted to identify treatment targets by examining the molecular and cellular processes involved in the initiation of allergic conjunctivitis. The threshold, linear rise, and plateau point in the connection between pollen levels and allergic conjunctivitis symptoms have also been studied.

In the past, intact pollen grains were counted to correlate patient symptoms to allergen exposure. It has been difficult, however, to establish a dose–response connection between pollen grain exposure and allergic conjunctivitis. Ocular allergies have been shown to cause a two-phase response, including early-phase and late-phase IgE-mediated responses. Pollen sensitization is caused by a combination of pollen exposure over time in a genetically susceptible individual. Symptoms, on the other hand, appear to reach an asymptotic threshold at which clinical severity plateaus. More research is needed to accurately characterise pollen sensitivity variations between plant species.