On 5 September 2015, a Boeing 737-800 was about to commence descent on a non-precision final approach at Porto in VMC when a green laser was directed at the aircraft. The Pilot Flying responded rapidly by shielding his eyes and was unaffected but the other pilot looked up, sustained flash blindness and crew coordination was compromised. Subsequently, the approach became unstable and a go around to an uneventful approach to the reciprocal runway direction was completed. The subsequent Investigation noted the use of increasingly powerful green lasers in this way and that such use was not contrary to Portuguese law.