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5 Cards in this Set
- Front
- Back
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We blink for __ seconds, every _-_ seconds.
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for 0.3 seconds, every 2-10 seconds
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How many muscles are needed to control eye movements in each eye?
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6
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How many times do we blink per day?
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approximately 20,000 times a day
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Every day blinking allows the eye to do what for approximately 30 minutes .
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close
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How much of the eye is open to external enviroment?
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1/6
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