At night time when I shine my laser at a white wall, you can clearly see the dot no matter where you move it

however during a sunny day, I point the laser pointer at a white wall and I can only ever see the laser's dot where my vision is fixated, IE a small foot by foot area on the wall

If I move my head with the dot, I can see it wherever it is

but If I keep my sight fixed to one spot, and move the dot around, it disappears when it's not in the foot by foot area i'm looking at

Could someone tell me why, I tried googling it lol

Edit - The wall is probably 15 feet away

This post was edited by Asexual on Jul 7 2013 12:53pm

I imagine it has to do with the way the eyes work. Because cones are concentrated in a particular spot in the eye, outside of this vision range color is hard to detect. Red is also a color used at night during astronomy because it doesnt effect the iris, which could have something to do with it.

Something you can try, which is like a reverse effect.

Look at the sky at night and "watch" your peripheral vision; you should see quite a few stars. But, look at them directly and they are no longer visible.

tl;dr - Its due to the biology of your eye.

This post was edited by khemist on Jul 7 2013 02:18pm

three effects:
1) in the middle of the eye's vision you have a much better resolution than not in the middle of the eye's vision
2) not in the middle of the eye's vision you are colorblind. if you think you see color at the end of your eye's vision, then it's only the color which is stored in your memory.
3) correlation. when you see multiple images where the dot is at the same point but the wall has always a different color, then you can take the "mean" value of all those images. the dot will always be as same as strong, but the noise in the background (the wall in this example) doesn't correlate between the pictures. therefore noise can be reduced. so it's your brain that uses a time-dependant filter.

Ahh ok, thank you for the answers