What causes bloodshot eyes?

Eye bloodshot is caused by conjunctival congestion, that is, conjunctival tissue telangiectasia, increased diameter, increased blood flow caused by. Many reasons can cause conjunctival congestion, more common are the following: First, due to infectious diseases of the eye, such as bacterial conjunctivitis, bacterial keratitis, viral conjunctivitis, viral keratitis. Second, due to allergic reactions in the eyes, such as spring catarrhal conjunctivitis, allergic conjunctivitis, etc. Third, due to a sharp rise in intraocular pressure, such as acute angle-closure glaucoma attack. Fourth, due to dry eyes, fatigue and other eye irritation caused by reactive conjunctival congestion. Fifth, due to external eye stimulation, such as rubbing eyes caused by reactive conjunctival congestion.