Laser dangers: What happens when a light is beamed at a pilot?
Increasingly powerful lasers aimed at planes can blind, dazzle and distract pilots during critical stages of flying - even after the beams have left the cockpit, a pilots' union has said.
The British Airline Pilots Association said the laser beam that forced a New York-bound Virgin Atlantic flight to return to London Heathrow will have put the aircraft, its crew and the 252 passengers on board at risk.
Police are continuing to investigate the source of the beam that left the plane's co-pilot unwell following the incident on Sunday.
Video report by Sally Lockwood
Balpa said pilots face several dangers during and after a laser is beamed into a cockpit:
Temporary vision loss associated with flash blindness
Glare
An after-image
An image left in the visual field after exposure to a bright light
Other forms of "visual interference that persist" after the beam has gone
The union's general secretary Jim McAuslan emphasised Sunday's attack on the Virgin flight was "not an isolated incident" and said "more needs to be done" to tackle the growing use of lasers against aircraft.
Around 9,000 laser incidents across the country were reported to the UK Civil Aviation Authority between 2009 and June 2015 despite the reckless action being made a criminal offence in 2010.
"Aircraft are attacked with lasers at an alarming rate and with lasers with ever-increasing strength," Mr McAuslan said.
In November 2015 it was reported that the eye of a British Airways pilot was damaged by a "military" strength laser which had been shone into the cockpit of his aircraft earlier in the year.