Flight BA759 from Bergen, in Norway, was struck by a green laser around 9:20pm on Monday morning as it came in to land at Britain's busiest international hub.
The lasers, which can be purchased online, can blind pilots and cause irreversible eye damage.
There are also fears the powerful laser pens – which can reach a power of seven watts – could be used by ISIS terrorists to bring down packed passenger planes.
Dr Steve Schallhorn, Chief Medical Director at Optical Express and a former US Navy pilot, said: "Laser attacks on pilots are exploding and could lead to a terrible tragedy if people continue to target aircraft.
"The problem is that I’m not sure that people who misuse powerful laser pens actually understand the harmful effect they can have on vision.
“Sudden exposure to a laser beam during a critical phase of flight such as take-off or landing could seriously distract or disorient a pilot, causing a disruption in concentration or instrument scanning.
“And when viewed directly, powerful lasers can cause irreversible eye injury by burning the retina."
There are also fears drones purchased online could bring down helicopters over busy parts of London, Express reported.
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