Question

The image formed by the eye lens on the retina is
A. Real, upright and enlarged
B. Real, upright and diminished
C. Real, inverted and diminished
D. Virtual, inverted and diminished

Answer 1

Hint: We should first check whether the image in the human eye formed on a screen or not to determine the real or virtual nature of image. Then check the type of lens in the human eye to determine the erect or inverted nature of the image. Then calculate the magnification of the image formed by the eye lens for the minimum distance of distinct vision to check the magnified or diminished nature of the image.

Complete answer:
We are asked to determine the nature of the image formed by the eye lens on the retina in the human eye.We have given that the image of an object seen by the human eye is formed on the retina of the eye means the image is formed on the screen. The image which is formed on the screen is always a real image.Hence, the image formed on the retina of the human eye is real.

We know that the lens in the human eye is a convex lens. The image formed by the convex lens is always inverted. Hence, the image formed on the retina of the human eye is inverted.We know that the minimum distance of an object for the distinct vision is 25 cm and this distance acts as the object distance of the human eye. The minimum distance in the human eye where the clear image of the object seen by the human eye is formed is 23 cm as the diameter of the human eye is 23 cm.The magnification of the lens is given by
\[m = \dfrac{v}{u}\]
\[ \Rightarrow m = \dfrac{{23\,{\text{cm}}}}{{25\,{\text{cm}}}}\]
\[ \Rightarrow m = 0.92\]

From the above equation, we can see that the magnification of the image formed by the eye lens on the retina for the object at the minimum distance of distinct vision is less than 1.Hence, the image formed by the eye lens on the retina is diminished.Therefore, the image formed by the eye lens on retina is real, inverted and diminished.

Hence, the correct option is C.

Note: The students should not get confused whether the image formed by the eye lens is magnified or diminished for the larger object distances from the eye lens as the image formed is always diminished. This is because for any object distance, the image distance is always small and the magnification will always be less than 1 making the image diminished.