Officials with airline pilots unions say the government should be doing more to alert them to incidents involving lasers (search) and to provide guidance about how best to protect themselves against beams that can blind.

At least eight recent incidents involve lasers being pointed at aircraft cockpits as they approached for landings. No one was hurt and all the aircraft landed safely.

Denis Breslin, an American Airlines captain, said pilots learned about the incidents only through the news media. He said the government should have a way to alert pilots so they can take precautions.

"Pilots want a generalized warning and training. I think that's not too much to ask," said Breslin, first vice president of the Allied Pilots Association (search).

Dennis Dolan, the top security coordinator for the Air Line Pilots Association (search), the largest pilots union, said pilots need to find out about recent incidents in their preflight briefings so they can prepare to react if confronted by a similar event.

Federal Aviation Administration (search) spokeswoman Laura Brown said the agency is very concerned about the safety of pilots, passengers and the rest of the flight crew. "We're putting the finishing touches on fresh advice for pilots," she said.

An FAA study released in June found that most pilots subjected to a laser flash in a simulator reported temporary visual impairment and brief distraction.

Of the hundreds of cases in the past in which airplane cockpits have been illuminated by lasers, none resulted in an accident, the study said.

The study concluded that "a laser attack could be quickly deployed and withdrawn, leaving no obvious collateral damage or projectile residue, and would be difficult to detect and defend against." A laser that's powerful enough could blind flight crews, resulting on a crash, the study said.

The FBI and Homeland Security Department (search) sent a memo to law enforcement agencies last month saying evidence indicates terrorists have considered using lasers as weapons. But federal officials have found no evidence the current incidents are part of a terrorist plot.

Breslin said pilots have some guidelines for what to do if hit with certain kinds of lasers. For example, if they see a red or green light, they can shield their eyes.

Different protections are used for different kinds of lasers, and pilots want to know what they are, he said. Ultraviolet beams, for example, can be filtered out with sun shades.

Shaoul Ezekiel (search), Massachusetts Institute of Technology professor emeritus of laser science, said a "pulse" laser that emits a short burst of light is especially dangerous because there's no chance for pilots to look away.

"For pulse lasers, you haven't got a chance," Ezekiel said. "All it takes is one blast and it's too late."

Putting louvers on the windscreen could reduce the probability that a laser would blind a pilot, he said.

John Nance, a former pilot and aviation safety consultant, said military-grade lasers can actually punch through the back of the retina and kill the victim by causing a cerebral hemorrhage.

Nance said he is concerned that some of the recent laser incidents could be terrorists testing laser equipment in preparation for an attack.

"They'll be looking to blow out the eyes of a pilot," he said.