Why does nearly shutting my eyes create a vertical illusion?

  • 1 Replies
  • 1532 Views

0 Members and 1 Guest are viewing this topic.

*

Vatsal

  • Guest
Vatsal asked the Naked Scientists:
   
If i close my eyes 80%-90% and watch a source of light (moon,street light), why does there appear to be a light ray going straight "up" from the source, rather than in any other direction?

If not familiar, you can try it right now by looking at, say, a window and closing your eyes to see the vertical effect.

What do you think?
« Last Edit: 24/04/2010 14:30:03 by _system »

*

Offline RD

  • Neilep Level Member
  • ******
  • 8175
    • View Profile
Why does nearly shutting my eyes create a vertical illusion?
« Reply #1 on: 24/04/2010 16:08:42 »
If the ray only occurs when you squint it is probably the result of diffraction at the straight(ish) edge of your eyelid which is then over your pupil.

[attachment=8451]
« Last Edit: 24/04/2010 17:01:48 by RD »