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schematic representation

Here is a picture I drew using Photoshop ;)

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interesting that you see hexagonal shapes. Hexagons often appear in 2D sensory processing due to its relation to sphere packing. – Memming Nov 5 '14 at 1:48

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up vote 9 down vote accepted


Wikipedia/Phosphene gives an explanation for occurrence of Phosphenes:


So seeing flashes of light can be due to:

  1. Blood shifting.
  2. Low blood sugar(causes weakness).
  3. Head trauma.
  4. Headache.


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It could be posterior detachment of the vitreous humor. Stress on the optic nerve caused by motion of the vitreous humor inside the eye can lead to the sensation of lights. And since the nerve is circular, you see a pattern of circular light. Normally its not serious, and many people experience it as age progresses. If you are not hydrating well during your climbing that might also be aggravating it. To be safe you should have an eye doc check you out though since there is slight risk it could lead to retinal detachment.

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This is very much like calling out "Zebra!" when you hear hoof beats (unless you happen to live on the grasslands of eastern and southern Africa. In that case, it's more like calling out "Caribou!" – anongoodnurse Jun 6 at 0:43
@anongoodnurse I'm also a climber, a runner, experience dehydration and on occasion experience the same light sensations when I press my eyelids tight suddenly or turn my head suddenly left to right at night. And this is what my doctor diagnosed. So what are you suggesting might be the issue otherwise besides grassland animals? – docscience Jun 6 at 5:17
What your doctor said doesn't carry much weight with me. They and I are of differing opinions. I don't think I could be any clearer expressing my opinion. If every time someone who exerted themselves saw lights it turned out to be a pulling on the retina, opthalmologists would be more common than dirt. – anongoodnurse Jun 9 at 5:41

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