Where should you be looking when you change objective lenses?

When changing objective lenses on a microscope, you should look at the specimen through the eyepiece rather than directly at the objective lenses. This allows you to ensure proper alignment and focus without risking damage to the slide or the lenses. It's also important to start with the lowest power objective to locate the specimen before switching to higher magnifications. Always handle the lenses carefully to avoid any misalignment or scratches.