SHASHWAT PRATAP SING said:
then my image must be forming behind me then how my eyes are able to see my real image in the mirror….
You really need to work on your description. Say exactly what you mean. Say exactly what each picture shows.
Try to avoid phrases like "image must be forming". If you are standing still the image is either there or it is not. It is not "forming". Try to avoid phrases like "real image in the mirror". The real image is not in the mirror. It is behind your head.
You have provided a number of pictures. Let us go through them slowly. Let us identify carefully what they show.
The first picture is of someone standing nose to mirror. There are two locations marked on the floor. One is marked "C". One assumes that this is at the center of curvature of the concave mirror. The other is marked "F". One assumes that this is at the focal length of the concave mirror.
This impression is reinforced by the fact that the distance from the mirror to C is approximately double the distance from the mirror to F.
But you are not asking about the situation in the first picture. So that picture is mostly wasted.The second picture is of someone standing between the focal point F and the center of curvature C. We see a blue shape drawn in space behind the person. One assumes that this is the place where the [inverted] real image of the person would form.
The person stands in the way of some of the reflected light that might otherwise go into forming this real image. As a result, the real image may not be viewable from all angles. However, this detail is irrelevant to the question that we are trying to address. Let us ignore that situation and proceed.The third picture is the same as the first but without the "C" and "F" labels drawn in. We can ignore it.The fourth picture is the same as the second. But instead of "C" and "F" labels and an image drawn behind the person, we have an arrow in front of him pointing toward the mirror.
This would appear to be an attempt to depict the person's line of sight toward the mirror.The final picture appears to have been taken from a little to one side as the man stands in the position depicted in the second and fourth pictures. That is, it was taken while the man is standing between the C and the F. It shows an inverted image.
This appears to be an attempt to show what the person himself sees. I may be mistaken, but that might be the camera's reflection in the person's right hand.If I understand your concern, it is that if we are looking away from a real image, we might not expect to be able to see that image. Certainly, our intuitive expectations learned from everyday life tend to support this. If person is standing behind me, I cannot see them when I am looking toward the front. If an image exists behind me, I might not expect to see it when I am looking toward the front.
This expectation is incorrect. The photographic evidence you have provided demonstrates that it is incorrect.
The light rays that hit your eyes are light rays that would have converged at the real image behind your head. But they did not converge there. Your eyes were in the way. The lens in your eyes (or in your camera) caused them to converge on your retina (or on the photodetector array in your camera) instead.
You "see" the image because the pattern of illumination on the retina (or on the photodetector array) corresponds to the shape of the person.
Human eyes are not designed to be able to clearly image converging light rays. It requires that they relax to a focal length longer than the distance from lens to retina. A focal length equal to the retinal distance would allow one to clearly focus on objects "at infinity". A shorter focal length allows one to focus on objects closer in. A longer focal length allows one to focus on images corresponding to convergent light rays -- that is real images behind the head.
There is no evolutionary call for eyeball lenses that can focus out past infinity. And little technical call for cell phone lenses that can do the same. The cell phone image of the reflected inverted man is not sharp. But with a narrow aperture, one can push the limits.
