dotted circles of confusion

[McCrunchy]

Hello,

 

I'm short-sighted. When I look at a small light source from a distance, it appears as a disk (see "circle of confusion" in wikipedia), because I'm not correctly focused. However, I noticed it's a textured circle, with lighter and darker spots, each a having a size ~ 1/10 - 1/20 th the diameter of the circle of confusion ( it looks a bit like the speckles in

http://en.wikipedia.org/wiki/Speckle_pattern ). Does anyone know what is the origin of this phenomenon ?

 

The texture doesn't change upon blinking (ie, moving small particles on the surface of my eye). The texture appears regardless of color (white, green or red LEDs were used).

 

Thanks for your help,

 

McCrunch

[insane_alien]

i get this too.

 

i think it is possibly interference as with the speckle pattern but i have found no references for this so cannot be sure.

 

i'll be following this thread to see where it leads.

[John Cuthber]

I have seen the same thing. It's different fro my left and right eyes and I think it stays the same if I look to the side of the light (so the image falls on a different bit of the retina) it's hard to be certain.

I guess it's to do with the imperfections in the lens