Discipline: Animal Biology, Literacy/Folklore
Age Range: All ages, but you need at least two people — one person reading the story and the other person participating in the activity.
Estimated Time: 15 minutes
What you need: A flashlight or lamp; a dark room or an outside area at night
Instructions:
Place a hand over one eye like an eye patch. Turn the flashlight (or lamp) on and place it on the ground 5 feet in front of you. Making sure zero light is getting through to your covered eye, look at the items around you that the light is shining on or to the side of the light with your free eye for the duration of the night vision story — all while keeping one eye covered. At the end of the story, turn off the light, remove your hand and look around you.
Story:
Long ago, there was a group of pirates known as The Eye Patch Hunters, who were notorious for taking treasure and goods from enemy ships at night without being seen. Every pirate on the ship had both eyes except for one pirate named Patches. At night when Patches would sleep, he switched his patch over to his good eye and used it as a sleeping mask, blocking out all lingering light. One night, he heard a noise and he quickly switched his patch away from his good eye, ran onto the deck and peered into the black water. He saw a giant whale swimming right next to the ship. When his fellow pirates accompanied him on the deck, they were unable to see the whale because their eyes had not adjusted to the low light conditions like Patches’ eye. As quickly as the whale appeared, it dove back down into the depths of the sea. Patches felt bad that his fellow crew members did not get to see this once-in-a-lifetime opportunity. He wondered how he was able to see the whale when no one else could.
Over time, his good eye had adapted to total darkness as he slept with an eye patch giving him the ability to see better at night. On the other hand, his bunkmates had lantern light and moonlight seeping through their eyelids. Patches observed his fellow pirates and noticed that he was the only one wearing an eye patch.
One day, he decided to use his night vision to his advantage and he came up with the idea to start stealing from other ships at night. He cut leather eye patches out and gave them to each of his crew members. Every pirate started wearing eye patches; day by day each of their eyes adapted to total darkness. Now the pirates had the upper hand at night.
The pirates painted their ship black and wore all black clothing for camouflage. The ship was a pirate legend because a dense screen of fog always hid it even on the brightest and clearest of days. The Eye Patch Hunters would lurk in the shadows as they waited for a cargo ship to exit the port. They would follow the ship until nightfall. During the day, the pirate crew had eye patches on, allowing their covered eyes to adjust to total darkness while their free eye allowed them to see. Once the sun had set, the pirates would hoist the mainsail and speed toward their prey. The Eye Patch Hunter pirates threw lines with grappling hooks onto their enemy’s ship. The metal thuds from the hooks woke the enemy crew that was guarding the treasure, and in their sleepy stupor, complete chaos broke out because the pirates would send gunpowder flares into the sky. The bright light blinded the confused the crew, which gave The Eye Patch pirates the perfect opportunity to sneak on board unseen. Even when the flares died out, the other crew was unable to see in the darkness because their eyes had not adjusted. The Eye Patch Hunters sprang into action and switched their eye patches over to their other eye allowing them to easily find the goods and treasure. Before the enemy crew’s eyes adjusted, the pirates had already sailed away.
Key Questions
What is night vision?
Which animals have advanced night vision?
Why do these animals use night vision?
The Science of Biological Features and Night Vision
Certain animals, such as cats, have a mirror-like layer behind the retina called a tapetum lucidum — a shining layer that reflects visible light back through the retina. Have you ever seen an image of a deer or a cat with glowing green eyes? That glow is coming from the tapetum lucidum reflecting light.
There are photoreceptor features in eyeballs called rods and cones that serve different functions that allow humans and animals to see; however, some animals such as owls have adapted excellent vision in low light conditions by producing more rods than humans produce.
Rods sense dim and scattered light and do not produce color, and cones sense bright and focused light and do produce color.
Rhodopsin is a protein pigment in rods that is sensitive to light and increases vision in low light conditions. Animals such as owls have high amounts of rhodopsin in their rods.
Vocabulary
Tapetum Lucidum: the shining layer that reflects light back through the retina
Photoreceptor: a structure in a living organism, especially a sensory cell or sense organ, that responds to light falling on it
Rods: Photoreceptors that sense dim or scattered light
Cones: Photoreceptors that sense bright or focused light
Rhodopsin: Protein pigment in rods that is sensitive to light