Light bulbs are different in nature from lasers, as they are meant to emit lots of white light to illuminate a room. When you shine a laser into a light bulb when it's turned off, your students will be able to observe how the light bends and refracts as it moves through the curved glass of the bulb. The light bulb effectively alters the path of the laser. The path that the laser takes will be further affected by the bulb's glass coating.
Take a large bowl or similar container and fill it with water. Turn off all the lights in the classroom. Shine a hand held laser into the water. Your students will be able to observe that the light bends through the water. Water refracts light, and thus "bends" it. Even when the water is totally still, the laser won't go straight ahead as it does when it is being shown in the air.
You can explain to your students that we can see objects not only because of light, but by the way that light strikes them. This is how objects are given their color . On the other hand, if an object is opaque, then the light will shine through it. This might sound obvious enough, but it is difficult to see this in the daylight. With a laser, you can demonstrate this by turning off all the lights in the room and shining the laser onto various objects. Students can subsequently view what objects stop the laser and what objects allow the laser to shine through. You should also have the students observe whether the light diffuses or stays focused during the experiment.
Show how mirrors deflect lasers. Position your mirror in the opposite direction that you want the light deflected in. Point the laser to the mirror and watch as it deflects. For a more complicated and fun experiment, use several mirrors in your classroom, effectively erecting a "maze of mirrors" in which a single ray elicited by the laser is deflected in several different directions at once.