Pierre Gasly has revealed that a piece of debris hit his visor on the opening lap of today's Russian Grand Prix.
A number of incidents in recent races have seen the safety device lauded, having proved its worth, but today's incident will surely cause concern as one of the main points of the introduction of the halo was to prevent debris hitting drivers.
"I think Daniel lost a piece of carbon, which went straight into my visor, so this was really, really scary," said the Toro Rosso driver, who retired just 4 laps into the race having lost his front brakes.
"I thought it was going through and straight into my eye," he admitted, "and finally it touched the visor and then came into the cockpit. In Turn 4 I had to take the carbon piece and throw it from the cockpit.
"At the time I had like five-tenths of a second to see it flying and just hitting the visor, maybe a winglet that came from somewhere, I think contact with Daniel. But it came my way, pointing towards me and straight in my right eye.
"When I saw it coming first I was like, 'it's going through the visor'. Thankfully, the visor is really strong, it hit it and fell into the cockpit."
Asked how debris got past the halo, the Frenchman confirmed: "It came under. I will have a look. It was pretty scary.
"The visor seems to be pretty strong," he added, "but maybe we need to keep improving and try to make it as strong as possible. The speed as well has an effect on the impact. At that time I was coming out of Turn 2, so I wasn't so fast. Maybe the impact with it luckily wasn't as big as it would have been if I would have been at 300km/h."