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Fun Stuff- For you to
Believed is to see!
Do the following experiments to see and believe more cool things about the human eye!
Look into your own eye
To look into the clear substance called vitreous humors do the following:
Materials:
Pin
Cardboard (no bigger that 30cm by 30cm)
Source of bright light
Procedure:
Make a pinhole in a piece of cardboard.
Look at a bright light (make sure it is not bright enough to hurt your eyes) through the pinhole using one eye only.
You will see tiny transparent circles move across the pinhole. These "floaters" are mostly remains of dead blood cells. They have broken loose from surrounding tissue and swelled up by absorbing some of the vitreous humor. The pinhole acts like a lens and helps you to focus on the tiny spheres.
Look at your look of blood vessels shadows
You are about to see the same things that your own eye doctor see. See the shadow of these cells similar to your doctor peering into your eyes with a flashlight to examine the condition of these tiny blood vessels.
Materials:
Room with a blank wall and instruments to make the room dark (switch and bulb)
Eyes
Hand
Flashlight
Procedure:
Go to a dim room.
Cover one eye with your hand.
Shine the flashlight in the outside corner of the other eye while you look at a blank wall.
Wiggle the light back and forth for a while till you see network of lines on the wall.
These are the shadows of your retina blood vessels.The back of the eyeball is covered with a thin layer of light sensitive nerve cells, or photoreceptors. Seven out of every ten receptor cells in your entire body are photoreceptor cells. The area at the back of the eye containing the not so common type of cells is called the retina. This is because the retina has a net of tiny blood vessels that nourish the receptor cells making it easy to live there.
Why two?
Each of your eyes has a slightly different view of the world. Do the following and see for yourself!
Materials:
Index finger
Eyes
Procedure:
Hold your index finger up about 30cm/ 12 inches away from the end of your nose.
Open and close each eye as you look at your finger.
Notice what happens to the background behind your finger as you switch eyes. I t shifts to the left with your right eye open and to the right with your left eye open.
You are not aware of the two different views with both eyes open because your brain puts them together to form a single view. Also note that when using both eyes, you see depth. Using one eye only, you depth perception will not be accurate.
Another experiment proving the same is below.
Why Two Eyes?
Materials:
A pair of sunglasses or fake glasses
Some sort of a paper or napkin
Tape
Procedure:
Take the glasses and using the paper or napkin cover one of the shades or lenses using tape.
Put them on and walk around
See if you feel a bit odd and things don't seem quit the way they are.
Back Veiw
Image Source:Personal |
Front View
Image Source:Personal |
Look at the lens
Have a look at the crystalline lens in your eyes through your own eyes
Materials:
2-inch, square (5cm square) piece of wax paper or saran-wrap
Newspaper
Glass
Water
Straw
Procedure:
Place the wax paper over the newspaper. Look at the print on the newspaper . What does it look like?
Fill the glass with water
Use the straw to transfer a drop of water from the glass to the wax paper
Look at the printing through the water drop. What does it look like this time?
No saran wrap
Image Source:Personal |
Saran wrap
Image Source:Personal |
Water drop on saran wrap
Image Source:Personal |
More fun stuff to do:
Try changing the size of the drop of water. Do small drops or large drops give better magnification or let you see more of the print?
Explanation:
When you first look at the print through the wax paper or saran-wrap, the letters are the same size as the printed page. However, when you look tat the same letters through the drop of water, the letters look bigger. The drop acts as a lens to magnify the letters underneath. A lens is a piece of glass or other transparent substance with a curve surface that refracts or bends or brings together rays of light passing through it. Depending on how the lens is curved, objects viewed through a lens can appear smaller or larger.
Interesting Fact!
What does 20/20 vision mean?
If you have 20/20 vision (as rated by an eye care professional), that means you can see something clearly at 20 feet that you should be able to see at that distance. So, if your vision is 20/200 that means you can see something clearly at 20 feet that you should be able to see at 200 feet.
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