Glaucoma patients can present with a red eye due to various etiologies.  This lecture divides the causes into acute glaucoma covering angle closure, neovascular and uveitic, iatrogenic including drug allergy, prostaglandin analogue hyperemia and preservative sensitivity and post glaucoma surgery such as complications of blebitis, bleb leak, suture exposure, tube erosions and endophthalmitis.  By identifying the cause of the red eye, appropriate management strategies can be formulated and commenced.