Kittens can be exposed to the sun after they are born. When the kittens open their eyes 10 days after birth, they can see the sun. When taking care of the kittens, they can be exposed to the sun for no more than 1 hour. Inside, choosing soft, non-dazzling sunlight to illuminate the kittens can allow them to replenish moisture and feel warmth, which is beneficial to the growth of the kittens.