When our eyeballs grow

Matt: Do our eyes grow, or are we all born with a full-sized set? — W.B., San Diego

The usually all-knowing, all-seeing Matt Alice was blindsided on this one. Growing eyeballs? What nonsense, I figured. Where do you people get these fool questions? Well, it seems human eyeballs do grow. At birth, they’ve reached only about 80 percent of their full sparkly potential. Eyeballs are measured along their north-south axes; the axial length of the average newborn’s eye is 18 to 20mm. By age five, we’ve got our adult-size 25mm peepers.