Why Do Random Flickering Laser Patterns Appear When Viewed from an Angle?

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Random flickering laser patterns observed from an angle are attributed to speckle interference, which occurs when coherent light, like that from a laser, interacts with surfaces and creates a pattern of bright and dark spots. This phenomenon happens on the retina regardless of the focal point of the eyes, suggesting that the patterns are a result of the laser's coherence and the way light scatters. Low divergence in laser beams can contribute to the visibility of these patterns, as tightly focused beams maintain coherence over longer distances. The discussion highlights the complex interplay between light behavior and human perception. Understanding these patterns can enhance knowledge of optical phenomena and their effects on vision.
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Why is it that when looking at a laser (not directly, but from an angle) it is possible to see a pattern of spots which flicker around randomly?
 
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Thanks dst.
In the site above it says: "The speckle interference pattern forms on your retinas regardless of where your eyes are actually focused". How can this be? Is this a cause of low divergence?
 
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