Also note that the information on eye disease is only provided as an information service and does not replace examination by an eyecare professional. 4.2 Conjunctivitis Conjunctivitis is an inflammation of a mucous membrane and therefore in most types there is a red eye, thickening of the conjunctival tissue and some discharge of mucous or mucous and inflammatory cells. Typical bacterial conjunctivitis, is caused by the common staphylococcus and diplococcus pneumoniae to the less common organisms of the haemophilus group. Bacterial conductivities responds well to antibiotic treatment. Viral infections, sometimes caused by adenoviruses which are often involved in upper respiratory tract infections, cause inflammation of the membrane on the back of the eyelid.
Allergic conjunctivitis results from hypersensitivity to exogenous antigens.
There are many forms, with some examples being, profuse watering due to hay fever, chronic inflammation as a result of a reaction to locally applied drugs. The treatment is to remove the antigen and use of vasoconstrictors. There is generally a tense swelling with redness and pain, until the abscess escapes. Internal stye, tarsal cyst or chalazion is a chronic granuloma of the Meibomain gland of the eyelid. This manifests as a small hard spherical lump within the eyelid, often easily felt but not seen.