Actually eye irritation can be caused by many reasons, for instance, constructivists(pink eye), red eye, black eyes. And eye problems can be caused headaches, nasal obstruction and heart diseases.Well, if you have no such eye problems or some basic diseases, then your eye irritation has most commonly due to cold. Generally speaking, eye irritation follows eye pain, it really uncomfortable. My friend told me that someone who runs a fever or get cold may easily suffer infection. Then the best time for virus and bacteriosis to follow you is coming. Next your eyes, nose and throat will cause some problems. Finally, eye irritation and eye pain make a surprise attack on you. Of course, cold is not the only factor that let you suffer eye irritation. You'd better go to see a doctor to solute your confusion and take a thorough eye exam to determine the real reasons for your eye pain. By the way, eye strain and eye dry can cause several eye diseases, so take good a rest and stay fit when you feel uncomfortable on your eyes.