The main reason why puppies open their eyes after being born is because puppies are not fully developed at birth. Animals that are not fully developed at birth are known as altricial. A better understanding of altricial animals helps explain why puppies open their eyes after being born versus having eyes open immediately upon birth.
Altricial Versus Precocial Species
Puppies eyes open after birth for the simple fact that dogs are an altricial species. What this means is that, when puppies are born, they can't fend for themselves, and therefore, they totally depend on their mothers.
Newborn puppies can't see as their eyes are sealed shut and they can't hear, presumably because their ear canals are closed. On top of this, newborn puppies can't regulate their body temperature and they cannot urinate or defecate on their own. They totally depend on their moms for food through nursing and their motor skills are limited to crawling for very short distances.
This is in great contrast with animals that are precocial. Animals that are precocial see at birth and they are capable of, not only standing, but also moving around. Examples of newborn animals that are capable of standing up and walking within an hour of being born include foals, calves, lambs and piglets.
Many large prey animals are precocial due to their need to stick with their herds. Being capable of seeing, standing and walking provides them with an important survival advantage considering that they are very vulnerable beings and should therefore be able to escape from predators in the wild.
A dog's ancestors, on the other hand, raised puppies in special maternal dens, where they were protected, and being for the most part predators themselves, there was no great need to escape.
Did you know? In general, animals that are altricial usually belong to species whose gestational period is very brief (in dogs, pregnancy is on average just 58 to 63 days). This is in high contrast with animals that are precocial, whose gestational period is relatively long (in mares, pregnancy is on average 11-12 months).
Why Do Puppies Open Their Eyes After Being Born?
All animals who populate the world have evolved complex “strategies” for reproductive success, and the way they develop is purposely crafted in such a way as to optimize their chances for survival and perpetuation of the species.
Puppies open their eyes after being born for the simple fact that they are born in an underdeveloped state and are not mature yet enough to see.
When puppies are born, their eyes are still developing. Their eyes are extremely fragile and very vulnerable to the elements. Mother Nature has therefore sealed a puppy's eyes shut to protect them from bright lights, opportunistic pathogens and foreign particles such as dust, grit and general debris.
Any of these threats could potentially damage the delicate photoreceptors of a puppy's eyes and the developing optic mechanisms in the making, explains Tom Davis in the book " A Collection of Curious Puppy Behaviors."
As seen, puppy eyes do not open after birth for the simple fact that their neural system is not ready yet for processing visual information. This is likely the price to pay for a shortened gestation time.
On top of this, in order for a puppy's eyes to function well, it is necessary that they are exposed to a vast amount of visual exposure in the environment, explains Adam Miklosi in the book "Dog Behaviour, Evolution, and Cognition." This is something that wasn't very feasible back in the days puppies were raised in confined spaces such as maternal dens.
Puppies' Early Eye Development
Fortunately, mother dog (in most cases) takes very good care of her puppies during their first days of life when they need all the help they can get.
Then, around the ages of 10 and 14 days, puppies finally start opening their eyes and a whole new world unveils in front of them! This is when puppies move from the neonatal period to the transition period, a time of great exploration.
Although this is a very exciting time, it's important to consider that the eyes, once opened, are still in an immature state. Puppies have some vision at this time, but several more weeks must elapse before a puppy's eyes and eyesight are fully developed, approaching the visual ability of adult dogs.
As the eyes start developing, this a good time for breeders to begin exposing their pups to mild visual effects. For instance, the light from a television turned on may offer a variety of visual effects as the lights shift from one scene to the next.
Exposure to these visual stimuli seem to increase the puppy's brain activity as the eyes try to decode the new sights, points out Jerry Hope, in the book "The Breeder's Guide to Raising Superstar Dogs."
Generally, the eyes can be said to being close to being fully functional at around 10 weeks of age.
Did you know? The reason why puppy eyes are blue is because they lack melanin, the main pigment that gives dog eyes their typical color. It is estimated that puppy eyes will reach their final color when puppies are about two months of age.
Now That You Know...
As seen, puppies don't open their eyes at birth because it would be counterproductive to do so. Mother Nature knows best. However, not always things go well as planned. Here are a few issues to watch for.
- Some puppies may take slightly longer to open their eyes. Generally though, any eye not opening by 14 days would be suspicious.
- Not all puppies in the litter will open their eyes at the same time.
- Never pry the puppy's eyes open unless instructed by your vet due to medical reasons. Prying open immature eyes can cause permanent, irreversible damage.
- Watch for signs of trouble such as discharge from the eyes, presence of mucus or crusts over the eyelids preventing them from opening and any abnormal swellings. These are signs of problems (like infections or congenital defects) that warrant a vet check.
- Puppies may develop corneal ulcers when other pups scramble over them to nurse and scratch another pup's eyes with their sharp nails. Filing the tips of the nails with a nail file can help avoid this problem and prevents the pups from scratching mom during nursing.
- It is normal for muscles around the eyes to "blink" even when the eyes are not yet open. These "blinks" often occur as responses to light.
- Avoid taking pictures with flash when the pups are developing their eyes.
- If you are using a heat lamp, use it with caution during the eye-opening period. You may have to construct a hood with aluminum foil (punch several holes with pen) around the light to create a more subdued lighting condition, suggests Beth J. Finder Harris, in the book "Breeding a Litter."
- Some puppies with light skin pigment may react strongly to bright lights due to their eyelids being more transparent.
- Glistening, reflective eyes are indicative of the tear ducts working well. Premature puppies or puppies whose eyes open early may not have fully developed tear ducts. These pups may need an ophthalmic solution if their eyes appear dry and dull. Consult with your vet.