During the second half of the 2023 season finale at the Yas Marina Circuit, Lewis Hamilton and Pierre Gasly were flagged for investigation over a possible pitstop infringement. They were soon joined by Max Verstappen, Williams drivers Logan Sargeant and Alex Albon plus Alfa Romeo's Zhou Guanyu.
The FIA stewards said the matter would be investigated after the 58-lap race and further clarification from the governing body pointed out that the infringements were related to "pitcrew potentially not wearing the required eye protection during a stop".
After the race, the FIA stewards summoned all team managers about the rules breach.
Following the investigation and hearing, the stewards did not produce any penalties due to some evidence "in some cases insufficiently clear to determine" rule breaches, but all teams were reminded that "the safety of team members is paramount".
The stewards' report concluded: "All teams are requested to stress the importance of eye protection for all personnel working on a car and ensure that this Article is respected by all team members in the future."
Abu Dhabi's race is unique on the F1 calendar in that it starts under a setting sun and ends under complete darkness.
It therefore throws up unique visibility challenges for drivers and pitcrew, with the choice of visor tints more complicated than usual.
It is possible some pitcrew members had temporarily opened up their protective visors during the second set of pitstops as visibility in the pitlane got lower.
The season finale was won at a canter by Verstappen, who took his 19th win of the 2023 season out of 22 races.
Ferrari's Charles Leclerc finished second ahead of Mercedes man George Russell.
The second Red Bull of Sergio Perez finished second on the road, but was demoted to fourth after receiving a five-second penalty for a class with McLaren's Lando Norris.
Norris finished fifth ahead of team-mate Oscar Piastri.
