There are multiple causes for redness of the eye namely: - Airborne allergens (causing eye allergies) - Air pollution - Smoke (fire-related, second-hand cigarette smoke, etc.) - Dry air (arid climates, airplane cabins, office buildings, etc.) - Dust - Airborne fumes (gasoline, solvents, etc.) - Chemical exposure (chlorine in swimming pools, etc.) - Overexposure to sunlight (without UV-blocking sunglasses) - Dry eyes - Eye allergies - Pink eye (conjunctivitis) - Contact lens wear - Digital eye strain - Eye infections - Eye trauma or injury - Recent eye surgery (LASIK, cosmetic eye surgery, etc.) - Uveitis - Acute glaucoma - Corneal ulcer I would advise you to visit the opthalmologist so that he can be examined and undergo the necessary investigations to find the underlying cause and have it treated accordingly.