Do you know that the human eye can see between 2,000 and 3,000 stars in the sky if the night is clear? Yeah, Its a real fact about human eyesight. Suppose you had a clear, moonless night. How many stars could you see with the eye alone? There’s really no definitive answer to this question. No one has counted all the stars in the night sky, and astronomers use different numbers as theoretical estimates.Considering all the stars visible in all directions around Earth, the upper end on the estimates seems to be about 10,000 visible stars. Other estimates place the number of stars visible to the eye alone – surrounding the entire Earth – at more like 5,000. At any given time, half of Earth is in daylight. So only half the estimated number – say, between 5,000 and 2,500 stars – would be visible from Earth’s night side.