A cat is in the kitten stage of life from birth to one year. Developmental milestones usually begin a week after birth, when ear canals start to open. Eyes follow suit between eight and twelve days, opening fully by the second week. While natural variation and premature births may shift this timeline, these ranges are the standard. Notably, every kitten is born with what appear to be blue eyes. This is due to the absence of a pigment called melanin in the iris.
