We get water in our eyes whenever we feel emotional,sad,happy etc...and every mammal can cry.this is bcoz of the tear glands/hormones/chemicals present in our eyes.whenever we feel sad,emotional, happy our brain overreacts and the chemicals,hormones comes out inĀ  the form of tears.and the hormones/chemicals disappear fro our body through tears so after we cry we feel kinda calmed up.bcoz of these hormones vanishing away from our body...

hope this helps.pls mark as brainliest..