Other conditions, including conjunctivitis, have similar symptoms
The differential for redness of the eye includes conditions such as conjunctivitis, glaucoma, and keratitis.
Conjunctivitis of any form—bacterial, viral, allergic, or toxic—involves injection of both the palpebral and bulbar conjunctiva.
Acute angle closure glaucoma can involve symptoms of headache, malaise, nausea, and vomiting. In addition, the pupil is fixed in mid-dilation, and the cornea becomes hazy.
Anterior uveitis/iritis causes sensitivity to light in both the affected and unaffected eyes, as well as ciliary flush (a red ring around the iris). Typically, there is no eye discharge.
Bacterial keratitis causes foreign body sensation and purulent discharge. This form of keratitis usually occurs due to improper wear of contact lenses.
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