Preschool Biology Activity - Eye Dilation

Have you caught your preschooler blinking in the light or complaining about how bright it is after coming out a movie theatre? Or has your preschooler noticed that while star gazing, the longer they stay in the darkness, the more stars they can see? Would you like to explain how our eyes constantly adjust to darkness and light? After doing this easy experiment, preschoolers will understand how their pupils dilate so they can see in the dark. 

 

What the pupils in their eyes look like

That pupils change size depending on how much light there is

A preschooler

Something to cover one eye (an eye patch or a scarf will work)

A mirror

 

Step one: Have a preschooler cover one eye for a minute or two with the scarf or eye patch. Caution: Your preschooler's depth perception will be off, so don’t let them run around or go up and down stairs.

 

Step two: Send them outside, or put them in a room with lots of light.

 

Step three: After a minute or two, uncover your preschooler’s eye and let them look in a mirror. They should see their pupil dilate or change from large to small. This is a very fast change, so they will have to look quickly. 

 

If your preschooler’s having problems seeing the change in their own eye, cover your eye and try the experiment on yourself. Your preschooler may have an easier time seeing your eye change than theirs. 

 

Consider doing this experiment on yourself so preschoolers will notice the change in your eye rather than on themselves.