A 19-year-old boy has been sentenced by a California court to two and a half years in prison for throwing laser beams at two flying planes. In March last year, Adam Gardenhair launched a green laser on a business jet with a laser-pen. He then aimed the same beam at the Pasadina police helicopter that came to look for the source of the light.

According to the BBC, Mr. Adam is the second person in the United States to face imprisonment for pointing a laser at an aircraft. Adam Gardenhair responded in court last October, defending himself. Such acts have been considered a “federal crime” in the country since February 2012.

Those who have used laser-lights must have noticed that the device is capable of transmitting rays far and wide and its diameter increases with increasing distance. Then when a laser light falls on someone’s eye, it temporarily makes it difficult to see the surrounding material.

The pilot of the first aircraft to be hit by a laser was suffering from visual impairment for several hours, according to the California Attorney’s Central District. However, the helicopter pilot in question did not have any complications as he had resistant glass in his eyes. The Civil Aviation Authority (CAA) says such high-intensity lighting can cause serious difficulties for pilots, making it not uncommon for a major accident to occur.

Lately, there has been a growing trend in many parts of the world to emit laser beams at aircraft. The BBC reports that more than 4,500 complaints have been received in the last three years.