Why do people blink?
Each time the eyelids close, salty secretions from the tear glands are swept over the surface of the eye, flushing away small dust particles and lubricating the exposed portion of the eyeball. In essence, people blink because to cleanse and moisten the eye.
Below is an instruction that describes a task, paired with an input that provides further context. Write a response that appropriately completes the request.
### Instruction: Why do people blink?
### Input: 
### Response: Each time the eyelids close, salty secretions from the tear glands are swept over the surface of the eye, flushing away small dust particles and lubricating the exposed portion of the eyeball. In essence, people blink because to cleanse and moisten the eye.