During Which Stage of Growth Do Puppies Open Their Eyes?

Fact about stages of puppy growth
Newborn puppies take time to open their eyes. Their eyelids need to develop fully before they are ready to open their eyes.
Did You Know?
...that dogs have a third eyelid? It is actually a membrane (called nictitating membrane) which has horizontal movement rather than vertical, and it doubles up as a windshield wiper, protecting the dogs' eyes!
On average, puppies open their eyes 12 - 16 days after birth.
But this is the average time, so sometimes puppies may open their eyes a day or two earlier or later than that. It depends on the individual puppy. Sometimes in one litter, one puppy may open his eyes after 9 days, while another may open his after 14 days, and yet another will open his after 18 days. There is no established pattern to know when a puppy will open his eyes. Sometimes a pup may even open one eye before the other!
You can help your puppy...
If the puppy hasn't opened his eyes after 16 - 18 days, you can help him by cleaning his eyes. Sometimes pups find it difficult to open their eyes because of birth buildup that is on their lids and lashes, fusing their eyelids. Dip a cotton ball in warm water and very gently and lightly wipe the pup's eyes, to remove any buildup. This should make it easy for him to open his eyes. It should work the first time, but in case your puppy doesn't open his eyes the day you wipe them, try again the next day. Be gentle, keep your touch light and make sure the water is not too warm.

The same treatment can be given if there seems to be a swelling in the pup's eyes, and pus is oozing out. Using a q-tip dipped in warm saline water, very gently wipe his eyes in the outward direction, so that the pus oozes out from the corners. Clean this off with cotton balls dipped in warm water. You can put a drop or two of saline water in the infected eye(s), twice or thrice a day to clean it and remove the bacteria.
When is it time to go to the Vet?
If your puppy is 20 days old or more, and doesn't open his eyes, it is necessary to take him to the vet without wasting any more time. Timely action is necessary to avoid any complications regarding eyesight. At any cost, do not try and pry open your puppy's eyes.
So why does it take so many days for a puppy to open its eyes? The tear glands are located along the margin and also in the folds of the eyelids. If the eyes open too early it may disturb the development of the tear glands, thus hampering the production of tears. This results in a condition known as "puppy dry eye" and it requires medical treatment consisting antibiotics and ointments a couple of times a day, until the tear glands begin functioning properly.

The eyelids of a puppy have to develop fully before they are ready to open, since they have many functions. They not only protect the cornea, but also prevent the eyes from drying out. It is the eyelids that spread the tear film across the corneal surface. They determine the shape and size of the eyelid openings and also keep the light from hurting their sensitive eyes. The eyelids also produce tears and help in cleaning the eyes by spreading the tear film. The lachrymal glands situated in the folds of the eyelids produce thirty to sixty percent of the watery portion of the tear.
Interesting Trivia
► A puppy's eyesight continues to develop for a few weeks after he is born. Ditto with the hearing!

► When a puppy opens his eyes his eyesight is still not fully developed. His vision is fuzzy or blurry and focusing takes time.

► Dogs have more rod cells than cone cells in their eyes, giving them good night vision. But although they can detect motion at night, focusing is less so their vision is more blurred.

► The first few days after opening his eyes, a puppy can only make out lights and shadows. Not even shapes, really.

► Dogs have dichromatic vision, meaning two colors stand out prominently - green and blue.

► Dogs need sunglasses just like we do! And doggie sunglasses are called doggles!

► Most puppies are born with blue eyes and this color usually changes after 3 - 4 months, which is when they will turn a color that will stay for the rest of the pup's life. Sometimes the color may change twice!

► Dogs can get glasses too! They are usually near-sighted, i.e., myopic. Getting them glasses or contact lenses will solve the problem in case it is too severe!
As a word of caution, do not open your puppies eyes yourself. Either because you get impatient or because you want to peek at the color of his eyes. They may open in the center first and proceed to open slowly towards the corners. This is pretty normal and no cause for alarm. Be patient and wait for your puppy to be ready and open them on his own.