Your baby lives in a perplexing world, but some things are coming into focus. New research has shown that your baby now has 20/60 vision, although his brain isn't able to process all of its visual information yet. For the first time, his eyes are working together, giving him the gift of depth perception. Now when he reaches for a toy, he's less likely to miss by a mile. His eyes can also track moving objects. For him, watching a rolling ball is a new thrill. He's beginning to notice colors, so he'll take a newfound interest in a bright-red toy or a colorful picture book. If he doesn't seem interested in looking at new things or if his eyes don't seem to be working together, tell your baby's doctor.
Now that he has depth perception, he'll try to grab anything and everything within reach. He'll enjoy lying under a "baby gym" and swiping at the dangling toys. Give him rattles and rubber rings that he can hold, shake, and explore. He'll also have fun playing with pieces of yarn -- just be sure to watch him closely.
You may be surprised to see how much fun he can have with his feet. These "toys" used to be hard to catch, but now he can find them with ease. Just like everything else he can reach, his toes tend to end up in his mouth. You can make his feet even more interesting by attaching a rattle or another fun noisemaker to his ankle. He'll soon learn that a good kick produces fun results.
He may have a new fascination with his fingers, too. He'll watch them closely as they wrap around a toy, and he'll suck on them for good measure. If he seems to be gnawing on his fingers for much of the day, he may already be teething. Run your finger along his gum line and see if you can feel any bumps. His teeth are likely to start coming in between four and seven months.
His busy hands can be endlessly entertaining, but they can also get him into trouble. You have to make sure that he can never reach anything that might be dangerous. For example, you should never drink a hot beverage while holding him. He could easily knock that cup out of your hand.
He's making many other important strides. He should be able to lift and turn his head, an ability that lets him play close attention to the world around him. Contact his doctor if your baby doesn't turn his head to locate new sounds. If you help him into a sitting position, he should be able to hold himself up for a few seconds using his arms for support. If you lift him into a standing position, he should be able to put some weight on his legs. If he's an especially active kid, he may have already discovered how to roll from his stomach to his back. The initial roll may be accidental, but he'll soon enjoy doing it on purpose.
Sears, William and Martha. The Baby Book: Everything You Need to Know About Your Baby. From Birth to Age Two. 2003. Little, Brown and Co.
American Academy of Pediatrics. Caring for Your Baby and Young Child: Birth to Age Five. 2009. Bantam Books.
American Pregnancy Association. First year of development. http://www.americanpregnancy.org/firstyearoflife/firstyeardevelopment.html
Nemours Foundation. Teething tots. http://www.kidshealth.org/parent/general/teeth/teething.html