Why can you see ghosts with cow tears?

The world is big, and there is no wonder. What evidence do you have to prove that there are no ghosts? Science is not everything, just because people like you always want to explain everything with science, and some things can't be explained by science.

Cow tears can be cursed, but cow tears are hard to get, and animals will not cry easily.

Hell, there are many ways. You don't have to use cow tears.

And cow tears should only be painted on one eye, so that you can see if you have seen a ghost. If you draw both eyes, you won't see them, because some ghosts are similar to normal people.