Definition of Vernal conjunctivitis:

Vernal conjunctivitis is swelling (inflammation) of the outer lining of the eyes due to an allergic reaction.

Causes, incidence, and risk factors:

Vernal conjunctivitis often occurs in people with a strong family history of allergies. It is most common during the spring and summer.

The condition causes itchy, watery eyes. The underside of the eyelids may become rough and covered with bumps and a whitish mucus. The area around the cornea where the white of the eye and the cornea meet (limbus) may become rough and swollen. If this swelling and roughness moves over the cornea, it may cause scarring and decreased vision.