Double Vision
Imagine that you are looking out of your window and focusing on the sun. (
Green arrow shows what is being focused on
.)
Now imagine that there is a raindrop on the window and you focus on that instead.
Because the object you are focusing on (the raindrop) is much closer to you than the sun, you see 2 different images of the sun, a left one and a right one.
If you close your right eye, which image of the sun will disappear?
This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try
refreshing the page, (b) enabling javascript if it is disabled on your browser and,
finally, (c)
loading the
non-javascript version of this page
. We're sorry about the hassle.
1 solution
Imagine you are looking with one eye at a window with a raindrop in the center and the sun perfectly behind it.
If you were to move to the left while looking straight ahead you would see that the window and raindrop move quite far to the right while the sun only moves slightly to the right (as it is farther away).
Now if you were to move back to the center then to the right while looking straight ahead you would see that the window and raindrop move quite far to the left while the sun only moves slightly to the left.
Now treat the two images above as the images seen by the left and right eyes respectively. If you center the raindrop in each image (required for you to see a focused image of the window and raindrop) you will see that the sun seems to have moved to the left side for the left eye, and the right side for the right eye.
Combining these two images gives you the image seen when focusing on the raindrop.
Finally, removing the image from the right eye (simulating what would happen when that eye is closed) you get the image from the left eye...
Which shows that the right image of the sun disappears when you close your right eye.