Vernal conjunctivitis is a sight-threatening inflammation of the membrane covering the back of the eyelid (tarsal conjunctiva). It primarily affects children younger than 14, and at least twice as many boys as girls have the condition. Many patients with vernal conjunctivitis also have asthma, allergies or eczema. Allergens that come into contact with the eye are believed to be at the root of the condition. It affects both eyes (bilateral) and occurs most often in hot, dry climates during the spring and summer.  

Severe eye itchiness (pruritus) is a major symptom of vernal conjunctivitis. Large bumps (papillae) also typically appear in a cobblestone pattern on the membrane covering the back of the eyelid. In addition, tissue can become inflamed around the cornea (the transparent tissue at the front of the eye) where the white of the eye (sclera) and the cornea meet (limbus). This inflammation can scar the cornea and damage eyesight. This is the chief danger to vision of vernal conjunctivitis.

Symptoms of vernal conjunctivitis tend to be seasonal and often appear first in the spring. With proper medical attention, the condition is highly treatable and related vision damage is usually preventable.