<unk>  occurs when the clear layer of tissue lining the eyelids and covering the white of the eye (conjunctiva) become swollen or inflamed due to a reaction to pollen, dander, mold, or other allergy-causing substances.
Allergic conjunctivitis
Actinic conjunctivitis
Iridocorneal endothelial syndrome
Vernal keratoconjunctivitis
Superior limbic keratoconjunctivitis
Fungal keratitis
Corneal ulcer
Interstitial keratitis