Well, of course, you may get eye stye by sharing mascara with others. As we know that a stye is inflammation of the eyelid, usually inside one of the small glands lining the eyelid. And generally speaking, most of styes are caused by infection from bacteria. So if you share mascara with someone else, it can be dangerous for your eyes to be infected. And when your eyes are infected by some irritants, it is possible to have eye stye. So just do not share mascara with others. To treat it, you should just make sure your eyes are far from the bacteria, so that they can not be infected. Also, stress can cause it too, so having a good and relaxing rest is effective.
Yes, it is possible for you to get the eye stye because of sharing mascara. As we know, the makeup material should be used in personal. You should not share it with other people which will make the bacterium infection happen easily. You could get the invisible bacterium from the mascara. That is why you get the eye stye.
What ? you can't be serious. Are you sure you have shared mascara with someone who has got stye in the eye? Well,as a matter of fact, by doing this, you are very likely to suffer stye because stye is an infectious disease, which is quite serious. The point is that the bacteria will be on the mascara, and it would be transmitted to your eyes. So, what I recommend is trying to get some immediate exam and take some effective measures before it goes worse.