The Science of Tears

1. Is crying only associated with sadness?

1.1. People do cry when they are sad, but the also cry when extremely happy.

1.2. Some people cry when they laugh too hard at something or someone.

1.3. Sometimes tears just slip out when yawning, coughing, sneezing, etc.

2. What exactly are tears?

2.1. There are 3 different types of tears.

2.1.1. Basal tears

2.1.1.1. Necessary for eye health and vision.

2.1.1.2. Lubricate, nourish, and protect eyes.

2.1.2. Reflex tears

2.1.2.1. Form to protect eyes from irritants

2.1.2.2. Wash away debris and help fight bacteria

2.1.2.3. Can also be triggered by the wind and onions.

2.1.3. Emotional tears

2.1.3.1. Occur when extremely sad or very happy.

3. Why do people cry?

3.1. Overwhelming emotions can cause tears.

3.2. Being really sad

3.2.1. Contains higher levels of stress hormones

3.3. Being really happy

3.4. Laughing too hard

3.5. Scientists are baffled how and why tears help you.

4. Importance of tears?

4.1. Provides nutrients and oxygen for the eye.

4.2. They remove waste products

4.3. Lubricate the eye

4.4. They also help to see better by smoothing irregularities on the surface of the eye.