Mascara sharing is okay, because there's nothing connect with the eyes if you are careful enough. However, you'd better not share the other makeup, it can be dangerous if their is anyone has infection.
Especially for our eyes. Then other diseases would delivered through saliva when people share lipstick. The makeup act as the carrier of bacterium.
Makeup is such a personal stuff, you'd better keep that as your own. However, you can share with your best friends if you don't mind. For other people that you have no idea, it's better not to share.
Definitely, sharing mascara with your friends is harmful and bad for your eyes. There is a chance of cross infection. As you have heard, virus can be transferred through any body fluids such as eye lid oils, tears and what not. Besides, other makeup brushes and applicators can easily carry bacteria from one person to another, and moist, dark containers allow such germs to thrive. As long as your roommates have an eye infection like conjunctivitis, then you could contract it. Just be careful not to share mascara, eyeliner and lip gloss with others. What's more, change your own mascara every 3 months at least too. Because it can get contaminated with a build up of bacteria.
Well, most of us are so happy and pleasure to share something wonderful with closed friends. Itâ€™s a good thing, but not all people can get a nice result because some accidents. To be infected by sharing mascara is one of them. Eyes are so weak that cosmetics are easy to do harmful to them. Sometimes you get pink eye or red eye just because your kindness. Cosmetics are very special medical things. The effects are difference among people. Some may feel good for them, while others allergic to them. And if your friends are suffering eye problems, for instance, pink eyes, dry eyes, black eyes and red eyes, be careful for your own eye health. Under this condition, the rate of getting infection will be increased. But not all times to share mascara is dangerous. So the best thing to do is ensure that your friends whether have eye diseases or not. However, in my view, no any eye shadow, eyeliner and mascara sharing with friends in a long time. May be it sounds selfish, but it's good to protect eyes.