Optics - Do I live in a smaller world with glasses?

  1. Okay, question, do I live in a smaller world than people with normal eyes?

    I noticed that when you look over your glasses (minus 3.5) half through the glasses and half to the real world, that the blurry real world is larger. My 28" computer screen seems 32", my cats head looks larger, my hands look larger, stuff like that. Like in this picture.

    So my glasses make the world smaller for me.

    But, my eyes are minus 3.5. I was wondering that if I had normal eyes if the world would be the same size as behind my glasses or the same size as my blurry world is now. After all, the refraction of a minus 3.5 eye is pretty off.


    {image removed due to size - Zz}
    Last edited by a moderator: Jan 25, 2013
  2. jcsd
  3. I guess it would depend on how your 'normal' eyes fixed the problem of your myopia. If the cornea/lens was less powerful, that would be a similar effect to wearing glasses (although not quite). If your eye was shorter then the magnification would be different.
  4. rcgldr

    rcgldr 7,696
    Homework Helper

    Part of the reason for the change in image size is due to the distance between your glasses and your pupils. The change in image size is reduced if you wear contact lenses.
  5. I like Serena

    I like Serena 6,183
    Homework Helper

    Gee, I never really thought about it.

    The only way we can tell what the world looks like is through our senses.
    We must accept what our senses tell us, since we have no other way to observe reality.

    We can only tell if we are in a bigger or smaller world, if we can compare.
    Just now you were able to compare.
    However, I think it is the other way around.
    Through your glasses you see the world as you'd see it if your eyes were "normal".
    Without your glasses you are living in a bigger world (that is slightly out of focus).
  6. rcgldr

    rcgldr 7,696
    Homework Helper

    To clarify my previous post, part of the issue is the distance between the lens and your retina. In this case it's a two lens system, the glasses and your cornea, but a major contributor to magnification or de-magnification is the distance from the lenses to your retina and the distance from the lens to the observed object. I think maximum effect occurs when the lens is at the midpoint between object and observer.

    Back to the person wearing the glasses, usually all imsages are de-magnified, since the image size on your retina is smaller than the actual size of an observed object. The variation is in the amount of demagnification.

    It's related to the thin lens equation:

    Last edited: Jan 25, 2013
  7. Borek

    Staff: Mentor

    Don't worry. When I put my reading glasses on world becomes apparently larger, so on average nothing changes.
  8. sophiecentaur

    sophiecentaur 14,725
    Science Advisor
    Gold Member

    Also, reading glasses can make people's eyes look larger and more attractive. Well - there are exceptions!
    Who else finds it annoying when actors wear obviously plane lenses in glasses, to give them a studious look? Girl takes off specs and lets hair down "Why, Miss Jones, you're beautiful" - fade up music.
  9. Borek

    Staff: Mentor

    I do. Especially as wearing ±0.25 glasses, or even just a spheric ones, would not hurt anyone.

    Can't say if it is more annoying when someone pretends to wear glasses, or pretends to smoke. Both look stupid.
  10. My vision was -6.0 before I got lasik. I can tell you that the world did get bigger after the surgery and I got rid of the glasses. It took some adjusting after the surgery.
  11. I'm actually working in my lab on the optics to see Ed Whitten's extra dimensions. Put these babies on and it will really shrink your world. I'll keep you posted.
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