Your kitten's eyes are closed during the first week of life because these little babies are born with undeveloped eyes. It takes a few days for them to develop enough to open their lids without damaging delicate tissues, and several weeks for your kitty's vision to develop fully.
Kittens' eyes are tightly shut at birth. It is not simply that they don't open their eyes -- they can't because the tissues of the eyeball do not finish "baking" until long after these little buns pop out of the oven. The kittens' eyelids form a protective seal until outer eye development is complete. Newborn kittens do not need to see -- they can find their mommy by sensing her touch and body heat, and latch onto her nipples by smell.
Weeks One and Two
In very rare cases, a kitten may briefly open its eyes as early as day 2, but most will not open their lids even a peek until day 8 at the earliest. Once the lids have unsealed, it takes 2 to 3 days for them to open fully, which happens for most kittens around day 14. Regardless of whether their eyelids have opened or not, most kittens are functionally blind for their first 2 weeks of life.
Open peepers are not the end of the story for kitten eye development. Sight develops gradually as the fluids around the lens of the eyeball turn from opaque to clear. It is not until the end of their third week of life that kittens are able to identify their mom by sight. Around week 5 their vision clears up, but sight still is not developed fully until week 10. Older kittens and adult cats have amazingly precise vision, even in light so low that, to us, it appears dark.
Cats' eyes actually are an outgrowth of their little kitty brains, with many different types of tissue, including nerve and muscle cells. It takes a while for these incredibly complex organs and their remarkable acuity to develop completely (and for your kitten to see well enough in the dark to do the elephant dance around your bed all night long).
Delicate Kitten Eyes
Baby kitty eyes are quite vulnerable to infection during the first 6 weeks of life. You should never touch closed kitten eyes or attempt to force a kitten's eyes open. Any swelling, bulging or discharge from kitten eyelids should be seen by a veterinarian immediately.
Angela Libal began writing professionally in 2005. She has published several books, specializing in zoology and animal husbandry. Libal holds a degree in behavioral science: animal science from Moorpark College, a Bachelor of Arts from Sarah Lawrence College and is a graduate student in cryptozoology.