Sharing makeup 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.
Hello, you'd better not share your eye makeup with others. Usually it is no problem and you will not get some contagious eye illness from others' eye make up. But if others do have some infection and some other eye problems, such as red eye, you are very likely to get it. So just by your own, it is the safest.
It is not safe to use other person's make up from the aspect of personal hygiene. You know the make up products are very close staff to get touch of people's skin, e.g. the eyelash make up, will contact with the area of eyes. If your fiend has got the pink eyes or other eyes disease relative to the infection or virus' cause, it is dangerous for you to use the polluted private staff of others. The make up is a channel that the disease spread. For the sake of health, please not use others make up, especially in the disease spreading's peak seasons of summer and spring.