ARE YOU LEFT OR RIGHT SIGHTED? 

Material: 

1. Two blank sheets of white paper.

2. A pencil

  

 

Future Quicktime Movie and photos of the demo to go here!

Procedure:

1. Make a hole in the center of one sheet of paper with a pencil.

2. Draw a black dot in the center of the other sheet of paper the size of a penny, and place this about 40 cm infront of you on the table.

3. With both eyes open, hold the sheet with the hole between your face and the sheet with the dot, and move the sheet about until the black dot can be seen through the hole.

4. While holding this sheet steady (while seeing the dot), close first your left eye and then your right. When does the dot disappear?

QUESTIONS:

1. Does the dot disappear after closing you left or right eye?

2. If the dot disappears when closing your left eye, are you left sighted or right sighted?

3. If the dot disappears when closing your right eye, are you left sighted or right sighted?

4. After determining that you are right sighted, does it make any difference whether you are closing your left eye or not in looking at the dot?

EXPLANATION:

For most people, the dot will disappear when closing the right eye. This indicates that most people are right sighted. It means that most people prefer to use their right eye over the left, if they are confronted with the option of using only one. In this case it means that those people can see the dot with both eyes open or with only the right eye open, but not with only the left eye. In other words, when both eyes are open, the left eye does no work. There is probably a connection between this phenomenon and the right handedness of most people, although it would be hard to say which is the cause and which is the effect.

APPLICATION: 

looking through a monocular microscope or telescope.

 

Biology Menu