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  • Category: Science

    Why do we perceive distant objects as smaller?


    Have a query about visualizing objects? Wondering why objects at a distance appear smaller? On this page, find the scientific reasons by experts for this phenomena.

    When we see an object we perceive it's size. A big sized object at a significant distance appears smaller while a small object near to us appears bigger.

    In short, we perceive far objects as smaller than the near objects.

    Can someone explain what is the mechanism in our eyes and brain which helps us in recognizing the size of an object?
  • #150329
    The visual angle is the angle a viewed object subtends at the eye, usually stated in degrees of arc. It also is called the object's angular size.The size of an object you are looking will be proportional to the visual angle. Objects at a distance appear smaller because the visual angle will become less ad the distance increases.It will be more acute with distance. The visual angle may be thought of as a triangle with the apex of the eye, and the distant object as its base.
    drrao
    always confident

  • #150347
    Refraction of light through space and through atmosphere makes a star look small and twinkling in appearance. Similarly refraction has a big hand in making things appear smaller here on earth. The other thing is angle of vision. Farther objects have long wave fronts.
    The angle is the ratio of size of the object and distance. Since the distance is longer than the size, the image formed is small and inverted.
    Your eyes adjust the inversion for you and you see a small steady image.

    The stronger a light shines the darker are the shadows around it.

  • #150348
    The size of an object perceived by the brain depends upon the size of image formed on the retina in the eye of a human being.

    Now, the size of the image on retina depends upon the angle that the object is making on the eye. For example a distant star makes a very very small angle (much less than 1 degree) on the eye and accordingly after passing through the eye lense the image of star on the retina is incredibly small. Hence it looks like a dot in the sky.

    On the contrary an object say a steel plate of 6 inch dia at a distance of 1 m from the eye will make an angle of about 8-9 degrees at eye and the image at retina will be much bigger than the earlier case of star. Hence the plate appears bigger.

    Thoughts exchanged is knowledge gained.

  • #150382
    It ca be explained by a practical example.
    Stand very close to a pole or pillar, slightly taller than you. To see the top of the pole or pillar, you have to look up. You will feel strain. Now move to some distance away from it and try to look at it. You may feel more comfortable. Again move away and try. You will feel that the more you are away from the object, the more comfortable you can look at it. This is because the angle of vision( the angle formed by the line coming from top of the object with the line of your eye and base of the object) becomes less reducing towards the base,so that you need not strain. This angle becomes less and less as the distance to the object becomes more and more. That is, the angle of vision becomes more acute. Hence the more far the object is the less in size it is perceived by our brain.

    (When you move nearer, the opposite will be happening)


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