(What is there more of the less you see? ———————> Darkness! -[1] )
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According to Odyssey’s article, Night Vision: Why you can see in the dark?:
“Eyes work by converting light energy into nerve impulses. These nerve impulses are sent to the brain, where we “make sense” of them. A certain pattern of light is a “tree,” another pattern is “my dad,” and so on.
An eye functions a lot like a camera. Light passes through the pupil — the part of the eye that appears black, but is really an opening. It is then focused by a lens, before it lands on the light-sensitive retina -a delicate membrane lining the inner eyeball and connected by the optic nerve to the brain.
Two kinds of cells share space on the retina: short, wide “cones” (7 million of them) and long, narrow “rods” (120 million of these). Each kind has its special uses.
Cones require a lot of light to work. Each one is connected to its own nerve fiber, so they help us to see fine detail. They are also sensitive to small differences in light wavelengths, which we call colors.
Rods work well even in low light. They do not sense colors or fine detail — though they are very sensitive to movement! The retinas of true nocturnal animals are packed with many more rods than ours have.
When your eyes are adapting to low light, several things happen. First, your pupil opens wide to let in as much light as possible. Then the rod cells turn off — there is not enough light for them to work at all. So at night we don’t see colors or fine detail. But we are more sensitive to tiny movements, which makes us jump even when leaves are just moving in the wind. Because there are more rods on the edges of your retina than In the middle, you often see best at night “out of the corner of your eye.” You learn to look slightly to one side of what you see.
True night vision develops slowly — it takes about 30 minutes for It to peak. Over a period of time in low light, your rod cells develop a reddish pigment called rhodopsin. This pigment increases the rods’ sensitivity enormously! But you still see differently than you do during daylight. Seeing at night is a lot like looking at a black and white TV with poor reception instead of a color set with cable.
If your dark-adapted eyes are exposed to bright light, the rhodopsin will instantly bleach white and you will lose your night vision until it has time to develop again.”
The article was retrieved from EBSCOhost Kids Search.
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Reference:
K-S, D., & , Initials. (2007). Night vision: why you can see in the dark?. Odyssey, 16(5), 11-11
[1] – Http://www.kidsjokes.co.uk/jokes/other/night_jokes_5.html. (1998). Retrieved from kidsjokes.co.uk: night jokes
If you want to read more on the topic, here are books that you can check out at our libraries.
All Rights Reserved, Picture Window Books, c2005.
Look! A Book About Sight by Dana Meachen Rau
Publisher: Minneapolis, Minn. : Picture Window Books, c2005.
Call No.: J 612.8 RAU
Click here to check for item availability
All Rights Reserved, PowerKids Press, 2008.
Exploring Light by Carol Ballard
Publisher: New York : PowerKids Press, 2008.
Call No.: J 535 BAL
Click here to check for item availability
All Rights Reserved, VT : Healing Arts Press, c2004.
How to improve your child’s eyesight naturally : a thoughtful parent’s guide by Janet Goodrich.
Publisher: Rochester, VT : Healing Arts Press, c2004.
Call No: English q617.70083 GOO -[HEA]
Click here to check for item availability
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For the availability of the above book titles, please check the library catalogue.
Ms Sharifah A. Latif
Assoc. Librarian, Children’s Services
.Fiction, eResources 
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