The cause of<unk>  is an<unk>  reaction of the body's immune system to an allergen.<unk>  is common in people who have other signs of<unk>  disease such as hay fever, asthma and eczema. Among the most common allergens that cause conjunctivitis are: * Pollen from trees, grass and ragweed * Animal skin and secretions such as saliva * Perfumes * Cosmetics * Skin medicines * Air pollution * Smoke * Dust mites * Balsam of Peru (used in food and drink for flavoring, in perfumes and toiletries for fragrance, and in medicine and pharmaceutical items for healing properties) * Eye drops (A reaction to preservatives in eye drops can cause toxic conjunctivitis) * Contact lens solution (some preservatives can irritate the eye over time resulting in conjunctivitis) * Contact lens (conjunctivitis is also caused by repeated mechanical irritation of the conjunctiva by contact lens wearers) Most cases of seasonal conjunctivitis are due to pollen and occur in the hay fever season, grass pollens in early summer and various other pollens and moulds may cause symptoms later in the summer.
Allergic conjunctivitis
Actinic conjunctivitis
Ligneous conjunctivitis
Acute hemorrhagic conjunctivitis
Ocular larva migrans
Phlyctenular keratoconjunctivitis
Sympathetic ophthalmia
Adenoviral keratoconjunctivitis