Blinking is an often overlooked yet simple way to keep your eyes fresh and being able to focus longer. Computer users and television watchers tend to blink less, especially when they are intently focused on something. Try it just now as a simple exercise. For the next two minutes blink every 3-4 seconds. After you have done this for two minutes, mentally take note of how your eyes feel, are they strained, relaxed, tired. Now try and not blink for 30 seconds at a time for two minutes. Do you feel any difference?
Whenever you blink your eyes are going into a brief period of darkness which helps to keep your eyes fresh and discharges previous information ready for new information, this helps to reduce eye strain.
Your blink rate can also help with your communication skills. Think about someone who looked at you intently and you possibly felt threatened by them. What you may have missed is the fact that they had stopped blinking.
When someone stops blinking and stares at you when you are talking it is a sign of aggression. However whenever you are talking to someone and they are blinking at a 3-4 second interval it is a sign of a relaxed and friendly listener.