When you look around, really look. Stare straight ahead and now,without moving your eyes , see if you can make out what's at the periphery. Do this regularly and you'll stimulate the neural and spatial centers of the brain, which can atrophy as you age.
When you look forward, also look around. When you walk down the street, don't just keep your eyes forward. Scan to the left and to the right. These actions can activate rarely used parts of the brain. That in turn can spur brain cell growth and new neural connections.