Why Do We Blink? — Reading Comprehension

Premium Resource

Grades

About This Reader

This educational reading passage, "The Science of Blinking," is designed for a 4th-grade audience to explain the simple but essential reasons why our bodies blink. It aligns with the Next Generation Science Standards (NGSS) for Life Science (LS1.A: Structure and Function), focusing on how the parts of the human body function to support life. The passage uses clear and simple language to define key terms like "reflex" and "tears," explaining how blinking acts as a natural cleaning and moisturizing system for our eyes. It also describes the protective role of blinking as a defense mechanism against foreign objects. The passage includes a fun fact to make the content engaging and memorable. With audio integration, this resource is perfect for a classroom lesson on the human body, providing a comprehensive and accessible way for students to learn about an everyday bodily function they often take for granted. The multiple-choice questions at different DOK levels test students' recall, inference, and application skills.

CONTENT PREVIEW

blink-eye — This picture shows the three main jobs of blinking: to keep our eyes moist with tears, to keep them clean from dust, and to protect them from harm.

Have you ever stopped to think about how often you blink? You might not realize it, but you do it a lot! An average person blinks about 15-20 times every minute. Blinking is a very important job for your eyes, and it's a reflex, which means your body does it automatically without you having to think about it, just like breathing.

There are a few big reasons why we blink. The first reason is to keep our eyes clean and healthy. Think of your eyelids as tiny windshield wipers for your eyes. Each time you blink, your eyelids spread a thin layer of tears across your eye. Tears are a special liquid that helps clean away tiny pieces of dust, dirt, or anything else that might have gotten into your eye. They also help fight germs to prevent infections.

The second reason is to keep your eyes moist. Just like a plant needs water, your eyes need moisture to stay healthy and comfortable. Without blinking, your eyes would get very dry and feel scratchy or sore. The tears that your eyelids spread also act as a lubricant, making it easy for your eyes to move around.

Lastly, blinking helps protect your eyes from harm. If something suddenly comes toward your face, like a stray bug or a baseball, your eyes will quickly and automatically blink shut. This quick reflex is called a "reflex blink," and it helps create a shield to protect your eyes from danger. It's an amazing natural defense system!

Fun Fact: A single blink is one of the fastest movements in the human body, lasting for only a fraction of a second—about one-tenth of a second!

What is a reflex?

A blink you do on purposeAn action your body does automaticallyA movement that is very slowSomething you have to think about doing

What are tears?

Small pieces of dustA type of germA special liquid that cleans and moistens your eyesThe muscles that close your eyes

Based on the passage, what might happen if you forget to blink while staring at a screen for a long time?

Your eyes would become soreYour eyes would produce more tearsYour eyes would get a lot of germsYour eyes would start seeing more clearly

How does blinking help your eyes stay clean?

By making your eyes wateryBy covering your eyes with eyelidsBy spreading tears to wash away dirtBy making your eyes move around

How is a reflex blink different from a regular blink?

A reflex blink is much slowerA reflex blink is used for cleaningA reflex blink is a reaction to a threatA reflex blink happens when you're sleeping

Imagine you're riding a bike and a small bug flies toward your eye. How does your body use the information from the passage to protect your eye?

It would tell your eyes to make more tearsIt would make you stop and close your eyes slowlyIt would trigger a reflex blink to quickly shut your eyeIt would make your eyes move faster to avoid the bug

Knowing that blinking keeps your eyes moist, what would you recommend to a friend who says their eyes feel dry and scratchy after reading a book for a long time?

Close their eyes and wait for them to stop feeling dryBlink more often and take breaks from readingPut a cold cloth on their eyesRub their eyes with their hands

How can you apply the knowledge from the passage to create a poster about eye health for your school's health fair?

Draw a picture of an eyeballList the names of all the eye partsWrite about blinking and its importance for keeping eyes cleanTell people to avoid things that can get in their eyes