types of disruptions may be due to corneal inflammations or physical trauma to the cornea, such as a foreign body. Pupillary abnormalities In an eye with iridocyclitis, (inflammation of both the iris and ciliary body), the involved pupil will be smaller than the uninvolved, due to reflex muscle spasm of the iris sphincter muscle. Generally, conjunctivitis does not affect the pupils. With acute angle-closure glaucoma, the pupil is generally fixed in mid-position, oval, and responds sluggishly to light, if at all. Shallow anterior chamber depth may indicate a predisposition to one form of glaucoma (narrow angle) but requires slit-lamp examination or other special techniques to determine it. In the presence of a "red eye", a shallow anterior chamber may indicate acute glaucoma, which requires immediate attention. Abnormal intraocular pressure Intraocular pressure should be measured as part of a routine eye examination. It is usually only elevated by iridocyclitis or acute-closure glaucoma, but not by relatively benign conditions. In iritis and traumatic perforating ocular injuries, the intraocular pressure is usually low. Severe pain Those with conjunctivitis may report mild irritation or scratchiness, but never extreme pain, which is an indicator of more serious disease such as keratitis, corneal ulceration, iridocyclitis, or acute glaucoma. Differential diagnosis Of the many causes, conjunctivitis is the most common. Others include: Usually nonurgent airborne eye irritants blepharitis – a usually chronic inflammation of the eyelids with scaling, sometimes resolving spontaneously drugs: medications or recreational drug use Cannabis dry eye syndrome – caused by either decreased tear production or increased tear film evaporation which may lead to irritation and redness subconjunctival hemorrhage – a sometimes dramatic, but usually harmless, bleeding underneath the conjunctiva most often from spontaneous rupture of the small, fragile blood vessels, commonly from a cough or sneeze inflamed pterygium – a benign, triangular, horizontal growth of the conjunctiva, arising from the inner side, at the level of contact of the upper and lower eyelids, associated with exposure to sunlight, low humidity and dust. It may be more common in occupations such as farming and welding. inflamed pinguecula – a yellow-white deposit close to the junction between the cornea and sclera, on the conjunctiva. It is most prevalent in tropical climates with much UV exposure. Although harmless, it can occasionally become inflamed. tiredness episcleritis – most often a mild, inflammatory disorder of the 'white' of the eye unassociated with eye complications in contrast to scleritis,