Laser pointers are small devices that emit a beam of light that projects a small, colored dot onto a surface. The main application of a laser pointer is to call attention to specific areas during a public presentation. However, laser pointers have been adapted to be used for fun as well. Upon inception, these devices once cost hundreds of dollars. However, the price in recent years has fallen dramatically to just a few dollars for some models.
There are two types of laser pointers. The ruby laser projects a red beam of light, resulting in a red dot. Inside the laser pointer is a ruby rod. On one end is a mirror and the other is a partially see-through mirror. A flash tube acts as a light source and is at one end of the rod. When a user presses a button on the side of the ruby laser pointer, the flash tube agitates atoms inside the rod. The atoms bounce off of the solid mirror and exit the laser pointer through the see-through one. This is what projects the beam of light onto a surface of the user's choosing.
Green laser pointers operate in the exact same way as ruby laser pointers. The sole exception is that instead of a ruby rod that emits a red-colored beam of light, there is a green rod that emits a green beam of light. The green rod is able to produce a more focused and powerful beam of light, which also makes it more dangerous. Pointing a green laser pointer directly into someone's eyes can quickly lead to blindness.