The prevalence of ocular allergy clearly is underappreciated and has been under diagnosed and undertreated. The ocular symptoms associated with the most common ocular allergy conditions, such as seasonal and perennial allergic conjunctivitis, are twice as likely to affect the allergy sufferer rather than nasal symptoms alone. The differential diagnosis of conjunctivitis is quite broad, with the most common forms associated with allergies, infections, and hormones. There are common features and some discerning features that, with a good history and examination, may provide a more focused and appropriate management.