A child can start exploring microscopes as early as three years old. While you shouldn’t put a top-of-the-line research tool into the hands of a toddler, many early-childhood-aged children can interact well with a simple microscope designed for kids. As they get older, you can introduce more complex ideas and, therefore, more complex models to their play and learning. Kids as young as 9 or 10 can successfully operate more advanced binocular-style microscopes to great effect.