Which of the senses is least developed in newborns?

The sense of vision is the least developed in newborns. At birth, infants can see but their vision is blurry, and they can only focus on objects about 8 to 12 inches away. Over the first few months, their visual acuity improves, and they begin to perceive colors and depth more clearly. In contrast, other senses, such as hearing and touch, are more developed at birth.