Is the focal point of our eye lens is on the retina? if it is so why dont we see point image of infinite object because light rays coming from them are parallel to each other and converges at focal point.
The focal length of the eye's lens changes based on what is being looked at. Ciliary muscles add or remove tensions from the lens to changes its shape, and thus its focal length. The closer the object, the shorter the focal length.
The light rays coming from one point on the object are indeed parallel. However, the sets of parallel rays from different points come from DIFFERENT DIRECTIONS.
By the way, the object "at infinity" is a generalization. Of course, all real objects we observe are positioned at a finite distance from our eye. It is just that the divergence of the rays is negligible in some sense. For example, given the size of the Earth (~13000 km) the divergence of light rays coming from the Sun are almost parallel because the Sun is being so far away (~150 000 000 km) compared to any, even impossibly large lens we could have on Earth.