All puppies are born with closed eyelids and ear canals, unable to see or hear. Puppies have short lives in the womb, emerging underdeveloped. Closed eyelids, for instance, protect developing eyes from damage until vision begins to develop.
Compared with most larger-sized mammals, dogs have very short pregnancies, lasting only about two months. So, puppies are born underdeveloped relative to other newborn mammals and require intense mothering. They cannot see or hear. They require help from mom to regulate their body temperatures and eliminate. Species that require lots of maternal care early in life are called altricial.
Puppies are born with underdeveloped, delicate eyes. Closed eyelids protect the eyes from damage due to dirt, abrasion, bacteria and bright light during and after birth. It will be more than a week before the lids open to slits.
A puppy's eyes open between 10 and 14 days of age. Vision develops steadily over the next few months, reaching maturity at four months of age. Although commonly thought to be colorblind, dogs can see blues and yellows in bright light. They can see much better in darkness than humans due to an abundance of low-light receptors and a reflective membrane behind the retina that reflects light back into the eye.
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