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Medical The lasting of the sense of vision

  1. May 10, 2007 #1
    My textbook states that if something i am looking at disappears for 0.1 second and appear again, I'll not able to perceive that it was not there for some moments. When an object build an image in my brain, the sense of vision lasts for one-tenth of a second. Doesn't it imply that if any other thing appear amidst of this interval and disappears- we will not able to be aware of their presence? Coz every image in our brain lasts for 0.1 second.
    Is'nt it right to assume that whatever we see must be present for 0.1 second in-front of our eye, to make visual perception?
    Last edited: May 10, 2007
  2. jcsd
  3. May 10, 2007 #2


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    If this were true than there people wouldn't be annoyed by CRT monitors with a refresh rate of 60hz or less. I find it extremely annoying. This is why 85hz is a common refresh rate for CRT monitors (for the few uf us still using them).

    The persistance of the eye / brain is sensitive to brightness. In a dark theater, 24 frames per second isn't annoying as long as there is no frame to frame jitter. However IMAX still runs at 60 frames per second for better visual quality.

    I had the impression that persitance was mostly an issue with how the eye converts light into mental images, not the brain.
  4. May 11, 2007 #3
    What is the threshold time(minimum time required) for visibility?
    That means a flash of light apears and disappears without letting you know that it was there. ;-)
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