Laser, is the English word "radiation of light amplification by stimulated emission of” short, also known as laser in Taiwan. It is human in the 20th century following the atomic energy, computers, semiconductors, another major after the invention, known as "the fastest knife, ""the most accurate scale”,” brightest light "and” exotic laser.”

Because the laser projector with a directional, high brightness, color, extremely pure, great energy density, making them in the military, industrial, commercial, technology, life, medical and other fields have been more widely used.

According to experts, the laser uses a very wide range, with laser light for stage decoration, classroom presentations with the laser projector and direct use of the laser pointer, Quiche bags under the eyes and correcting myopia laser scalpel, living or working with frequent CDs, laser printing and laser illumination for the Beijing Olympics the new laser projection television, laser has long been inextricably linked with our lives.

I searched the Internet free of advertising a green laser pointer, this product is mainly used for projection screen instructions to use in the classroom and lectures frequently, and its range of up to several hundred meters, power adjustable red laser beam is Pen ten times.

Experts expressed their concerns, "about 1 maw of laser products into the eyes is likely if the direct cause harm, and if prolonged exposure to the human eye under the green laser, especially when more than 5 mill watts of power, just a short few seconds may cause permanent eye injury. Like a green laser pointer with a teacher lectures and some power is relatively large, and the price is very cheap, if not pay attention, the children used to play will be very dangerous. "