I am sorry to hear that your friend got sore eyes. But If your friend's sore eyes because of pink eye ( also called red eyes), you shall stay away from him till he recovery because his core eyes will contagious. And usually, it is contagious only by contact when you rub or touch your eyes after you touch him.
Yes, it is. The sore eye is known as conjunctivitis, which is a highly contagious infection of the eyes. It's common caused by adenovirus, which starts with one eye and spreads to the other eye. In other words, it can spread quite fast, the contamination can be passed from eye to hand, and to eye again. Even it can be transferred from one person to another by hands to eyes, droplet. Or dust, wind, smoke, UV lights and other factors to allergy or irritant the eyes to lead to sore eyes.
It is hard to say whether sore eyes are really contagious, it all depends on what causes your friend's sore eyes. Generally speaking, sore eyes are not contagious except that sore eyes are caused by trachoma, pink eyes. Some times, sore eyes are caused by using eyes for a long time without stop and paying no attention to the health of eyes in daily life. What's more, trachoma and pink eyes do not contagious in daily communication, you should not share the same wash bowl and towel with your friends, and the sore eyes does not contagious by digestive system and the respiratory system. You should tell your friend to go to hospital to see a doctor as soon as possible to know what causes the sore eyes.
Yes . But if you just stay with the person who got sore eyes, you won't be infected. But if you have used his or her some articles for daily use, such as the towel and cup, or if you have contacted him and used your hands to rub your eyes, then you can get sore eyes easily.
Well, it is absolutely unnecessary to stay away from your friends. Your friend`s illness will only be infectious if you are too close to him, for example, if you touch the things that he touched and rub your eyes, you are likely to get sick. So my advice is that you will remind your friend to keep clean and wash his hands. Anyway, it is unwise to lose a friend right, so you'd better urge him to visit a doctor as soon as possible!