If you have no big eye problems, like the cataract or other eye problems, it will be ok for you to dye the eyebrows to make your eyes look beautiful. However, the material from the mascara cream will stimulate the skin around the eyes if your skin belongs to the sensitive one. It will not cause the blindness. But you should use it not at regular time.
Just dying eyebrows would not cause blindness. Up to now, I have never heard of this kind of news. Nowadays, technology for dying (no matter hair or what) develops mature and well, it should be safe to use the dying material. Yet you have to note that dying material is a kindly chemical which could be very irritated, it could be harmful if you get it into your eyes. After all, eyes are very safe and easy to get hurt. According to my knowledge, if you handle this in a safe way, it should not cause serious problems to your eyes. Don't worry. You can choose some beautiful color contact lenses to match your eyebrow color too. Hope you get a beautiful new look~
Dying eyebrow is a bad for our health because of the chemical factors which will cause cancer or other diseases. But don't worry, it won't make you blindness, and it won't be so badly unless you tried dying thing so frequently.
My suggestion is that do not dying your eyebrow, try another methods to change your eyebrow color.
Here is one of them. First, shave your eyebrow with a small razor blade, remember not to remove all of them, just shave off the mussy stuff. Then, you can pencil your eyebrow with the color you like.
You have to make sure the color you choose can match your hair color.