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The Relationship between the Eyes and Energy?

  1. Mar 8, 2006 #1

    gbg

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    Recently, I was reading through a psychology text book (Introduction to Psychology, James W. Kalat, 7th edition) and it mentions that when we see something using our eyes, energy goes into our eyes and energy does not come out of our eyes. Is this true?

    Based on what I know, light is a form of energy, it can behave like a particle at times, and like a wave at other times as well. When light hits an object, that it can be absorbed, reflected, transmitted, refracted or a combination of the four. Based on that, I think that energy not only comes into the eyes but also out of our eyes. When we see something, some of the light is transmitted into the eye and some is reflected (energy goes out) from the eye. As a result light (energy) is going into and out of our eyes simultaneously. In addition to that, the angle of which the light hits our eyes also affect whether the energy enters or leaves. Besides that light that enter our eyes can be scattered due to the surface of our pupil, so if the surface is not efficiently correct, light will scattered, with some transmitted into our eyes and some reflected away.

    I have not found any specific scientific journal articles that describe the relationship between light energy and the eyes. Please direct me to any resources that can help me understand the relationship between the eyes and energy. Thank you very much for your time,:smile:
     
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  3. Mar 8, 2006 #2

    chroot

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    Please do not double-post.

    You are correct that energy (in the form of light) both enters and leaves the eye.

    There is no such thing as a perfect absorber of radiation in the real world, though physicists often consider theoretically perfect absorbers (called blackbodies).

    The red-eye phenomenon that ruins photographs is caused by the retina reflecting some of the energy emitted by the camera's flash.

    Also, I should note that all objects produce thermal electromagnetic radiation with wavelengths corresponding to their temperatures. Our eyes, at about 300 kelvin, are constantly radiating in the infrared spectrum, losing energy to the (presumably cooler) room-temperature environment. The rest of our bodies radiate the same way.

    - Warren
     
  4. Mar 8, 2006 #3

    gbg

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    Thank you for your help. Do you know of any scientific article that support the fact that light energy both enters and leaves the eye?
     
  5. Mar 8, 2006 #4

    chroot

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    Honestly, I'd say it's too basic a concept to warrant an article. It's like asking if I can point you to an article proving that water's wet.

    If all you're trying to do is disprove your psychology book, you're already done. However, it's a psychology textbook, and probably shouldn't be considered authoritative on physics anyway.

    - Warren
     
  6. Mar 8, 2006 #5

    gbg

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    The reason that I need an article is because I need to prove to my teacher that my answer on my mc test is correct. I have talked to her about why I said energy comes in and out of the eyes but she wants further proof.
     
  7. Mar 8, 2006 #6

    chroot

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    How about this:

    You're effectively taking a picture of the back of the eye, which obviously involves light both entering and leaving the eye.

    http://en.wikipedia.org/wiki/Red-eye_effect

    - Warren
     
  8. Mar 8, 2006 #7

    Moonbear

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    *sigh* I don't know what's in the Introduction to Psychology text, but Kalat also has a Biological Psychology text that makes no such claim (of course my edition is rather old).

    If your teacher needs evidence that light also escapes back out of the eye, point out the phenomenon of animals having "glowing" eyes at night, in particular ruminants, such as deer. They have a reflective surface in the back of the eye that helps enhance their night vision, but also reflects light back out even more noticeably so that their eyes appear to glow if you shine a light at them at night.

    Also, if light shined into the eye was completely absorbed, optometrists would not be able to see anything when they examined your eyes...you can shine a light in and what reflects back out helps the doctor see the retina during an eye exam.

    Actually, here, try these:
    http://www.ncbi.nlm.nih.gov/entrez/...uids=15820514&query_hl=22&itool=pubmed_docsum

    http://www.ncbi.nlm.nih.gov/entrez/..._uids=8776488&query_hl=22&itool=pubmed_DocSum

    http://www.ncbi.nlm.nih.gov/entrez/..._uids=2375701&query_hl=22&itool=pubmed_DocSum

    http://www.ncbi.nlm.nih.gov/entrez/..._uids=7260483&query_hl=22&itool=pubmed_DocSum

    http://www.ncbi.nlm.nih.gov/entrez/...t_uids=409694&query_hl=22&itool=pubmed_DocSum

    These are just the abstracts (brief summaries) of the complete articles, but it should be enough to satisfy your teacher. The last one is straight to the point...reflection is precisely what they were measuring.
     
    Last edited: Mar 8, 2006
  9. Mar 8, 2006 #8

    gbg

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    Thank you very much for all your help
     
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