Thanks for the great question! As you may have already heard, the human body is made up of 60% water! I found an interesting website click here to see that further states that blood is 92% water, the human brain and muscles are 75% water, and even bones are 22% water!

Of the water that makes up your body, all of this water contains lots of salt ions, which are more commonly called electrolytes (but the water in our body is not nearly as salty as the ocean!). In fact, these electrolytes are so important for the human body that we need to replenish these salt ions when we lose them, for example by sweating. This is why athletes drink Gatoraid or Poweraid during intense workouts; athletes need to replenish the electrolytes as well as the water!

Since tears are made up of the water that comes out of your body, this is one reason that they are salty. Another reason that tears are salty is because salt ions are also very important for the proper function of your eyes. Tears not only contain salt ions, but also other materials that are important for proper eye function, including proteins that lubricate your eyes (proteins are molecules that are made by your body to perform many different functions). Here is a short website with a few facts about tears:

I hope that this answers your question, and keep the questions coming!

Reptiles use tears as a way of getting rid of excess salt in the body. It may have to do with the fact that water is a good environment for bacteria and whatnot to grow in, and having lots of salt in the water makes it a much less good environment.