Unspoken words for thought

Posts tagged ‘dilation’

Green Eyes In Beautiful Detail

Wrote a poem about green eyes before, here are two videos I made lately:

Did you think the eyes are smooth spheres? Macro view of this eye reveals a pattern that reminds me of craters.. Maybe on Alien territories 😛

What do the patterns of this iris remind you of? How about Mediterranean sea, or a bizarre suggestion by a friend- Petri dish or sperms surrounding an egg.

Ok, some descriptions don’t sound pretty… Nevertheless, how intricate are the designs of out eyes? Evolution has created endless forms most beautiful! Spare a moment to be grateful for our sight and these beautiful & well designed features…

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The iris is a contractile structure, consisting mainly of smooth muscle, surrounding the pupil. Light enters the eye through the pupil, and the iris regulates the amount of light by controlling the size of the pupil. The iris contains two groups of smooth muscles; a circular group called the sphincter pupillae, and a radial group called the dilator pupillae. When the sphincter pupillae contract, the iris decreases or constricts the size of the pupil. The dilator pupillae, innervated by sympathetic nerves from the superior cervical ganglion, cause the pupil to dilate when they contract. These muscles are sometimes referred to as intrinsic eye muscles. The sensory pathway (rod or cone, bipolar, ganglion) is linked with its counterpart in the other eye by a partial crossover of each eye’s fibers. This causes the effect in one eye to carry over to the other.

(Wikipedia)

Nature will bear the closest inspection. She invites us to lay our eye level with her smallest leaf, and take an insect view of its plain.

–Henry David Thoreau 

“The soul, fortunately, has an interpreter – often an unconscious but still a faithful interpreter – in the eye.” 

— Charlotte BrontĂ«, Jane Eyre

About weak points [of the Origin] I agree. The eye to this day gives me a cold shudder, but when I think of the fine known gradations, my reason tells me I ought to conquer the cold shudder.

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Pupil Constriction and Dilation

So the other week I bought some lens extensions for taking macro images as one of my hobbies is to take pictures of nature. I thought I’d give filming in HD ago and chose the eye as my subject because of it’s intricately beautiful design.

As you can see the video reveals details of the iris and pupil including their movements- constriction and dilation in this case. This didn’t happen to a friend’s eye that I initially filmed. I’m puzzled by this…

After some research and looking at other videos that people posted I came across things such as autonomic nervous system, galvanic response, adrenaline levels… Maybe the pupil is changing in size due to the blood circulation? However someone suggested it could just be the lights. Although additionally, I should point out that I am affected by myopia- essentially shortsightedness which might affect the constriction/dilation as well?

I’m still not sure what exactly causes this relatively fast paced change in size in the pupil & is wondering if many people have eyes that behave like this….

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