What if a puppy only opens one eye?
Most puppies have slightly different open times for each eye, generally separated by less than 2 hours. However, it is possible for a puppy to have one eye open on one day (say, a Monday) and the other eye not open until the next day (in this example, Tuesday). However, if one eye remains closed after the other has opened over 24 hours prior, you should take your puppy to a veterinarian for examination.
Sometimes puppies can be born with congenital structure issues in one eye that prevents the eye from opening naturally. Puppies are also quite susceptible to orbital bacterial infections, which can also cause an eye to not open as normal.