Many diseases can cause redness in the whites of the eyes, but ocular diseases, especially ocular infectious diseases, are one of the most common factors, such as blepharitis, conjunctivitis, keratitis, and sclerenitis. It is also important to rule out other non-infectious diseases such as foreign bodies on the eye surface, inversion or ectropion of the eyelid, dry eye, allergic conjunctivitis, refractive error, and visual fatigue to avoid delaying treatment.
In addition, ocular redness can also be caused by systemic diseases, such as hematologic diseases and hypertension, which can lead to recurrent subconjunctival hemorrhage, requiring a multidisciplinary consultation for a clear diagnosis if necessary.