Pathologies of each of the orbit, eyelid, conjunctiva, cornea , sclera, episclera and even the posterior uveal tract can all manifest as a red eye. As a result of the intimate relationship between the lid margin and the ocular surface, pathologies affecting the eyelids are common causes of red eye. Blepharitis Symptoms of blepharitis include burning, grittiness, mild photophobia, crusting and redness of the lid margins. These symptoms are characteristically worse in the morning. Corynebacterium is known to contribute to the pathogenesis .
Tear substitutes for patients with tear film instability as in posterior blepharitis.
Ectropion of the lower eyelid is horizontal lid laxity and loss of normal apposition of the lacrimal punctum on the surface of the globe. Treatment Heavy lubrication and strapping of the lids at night is usually adequate for mild cases. Entropion is the inward rotation of the eyelid margin towards the globe causing constant rubbing of the eyelashes on the cornea causing irritation, ulceration and pannus formation. Treatment - Mechanical epilation or electrocauterisation of those eyelashes rubbing on the corneal surface. The conjunctiva is the transparent connective tissue layer covering the white of the eye .Any inflammatory response therefore,which naturally includes vascular dilation and engorgement, will give the eye a red appearane .