The human eye forms the image of an object at its __________.

The human eye functions much like a camera. When light rays reflect off an object, they enter the eye through the cornea, the transparent outer covering. The cornea bends (refracts) the light and directs it toward the pupil, the small adjustable opening controlled by the iris, which regulates the amount of light entering the eye.

After passing through the pupil, light is further focused by the lens, which adjusts its shape to sharpen near or distant objects (a process called accommodation). The final destination of the focused light rays is the retina, the innermost lining at the back of the eye.

The retina is a thin layer containing millions of specialized light-sensitive cells:

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  Rods, which detect light intensity and are responsible for night and peripheral vision.

  
  


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  Cones, which detect color (red, green, and blue) and are responsible for sharp central vision in daylight.

  
  

When light strikes these photoreceptor cells, it is converted into electrical impulses. These impulses are transmitted via the optic nerve to the visual cortex of the brain, where they are interpreted as images.

It is important to note:

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  The image formed on the retina is real, inverted, and reduced in size.

  
  


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  The brain then processes this information and flips the image so we perceive it upright.

  
  

To clarify the options:

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  Cornea and lens help in focusing but do not form the final image.

  
  


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  Pupil is just an opening; it does not form images.

  
  


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  Iris controls the size of the pupil but does not play a direct role in image formation.

  
  


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  Retina is the correct site where the image is formed.

  
  

Thus, the human eye forms the image of an object at its retina (Option D). This is the fundamental principle of human vision.