Czechia’s Daniela Novakova #30 reacts after losing her mask in the first period against Canada during Semifinal Round action at the 2025 IIHF Ice Hockey U18 Women’s World Championship at Vantaa Trio Arena on January 11, 2025 in Vantaa, Finland.
photo: ©️ International Ice Hockey Federation / Micheline Veluvolu
IIHF study of vision helps referees develop, and prepare better
A referee can only call what he or she sees. But anyone who’s ever seen a hockey game knows that sometimes the on-ice officials miss calls, even though everyone else in the arena seems to have seen what happened.
As part of the continual development of officials, the IIHF has conducted studies on the referees’ vision. What do they actually see, and how do they make observations on the ice when things happen fast?
“We knew how fast officials can skate or run, or how much they could squat at the gym, so we wanted to go a little deeper and see if we had missed some part of the equation,” said Joel Hansson, Officiating Development Manager at the IIHF.
One of the studies the IIHF looked at was what makes great football players great and learned that Lionel Messi, for example, made much more frequent eye and head movements, to scan the field, than players that weren’t at his level. Other, similar studies have also highlighted the importance of scanning.
Together with specialist Lee Waters, the IIHF has provided the on-ice officials with special glasses in four junior tournaments – most lately at the IIHF Ice Hockey U18 Women's World Championship in Finland. The glasses have two cameras: one records the game events, or what the referees see, and the other the ref’s eyes.
“A red dot shows where the referee’s eyes are focused, and the size of the dot tells us how fully they’re focused on, say, a puck in the corner,” Hansson said.
“And we can tell that over the course of a tournament the focus changes. Early on, everyone’s very alert and focused, but as the tournament progresses, fatigue or stress affects them.”
The pressure on the cognitive brain also increases, which can lead to more decisions made on gut instinct, or by the reptile brain, if you will.
That knowledge can help with the officials’ game preparation and load management, according to Hansson. Maybe it’s best to give an official day off to make sure he or she is better prepared for the next game.
“We know they’re in shape, eat well, sleep well, but we also know they’re on the ice for the full 60 minutes, and have to make many, quick decisions," Hansson said. "One thing we’re looking into is how to, firstly, relax after a game, and secondly, warm up for a new game.”
Some people watch TV after a game, others read, or maybe play a video game, all activities in which the eyes are fed new stimuli.
“What we’re looking for are ways to help the officials to find new patterns and tools that they can use, for example, when warming up, especially their eyes," Hansson said. "We’ve looked into what is being done in Formula 1 racing, how they work with reaction times and so on.”
All this just to help officials to make better decisions.
The IIHF is the only sport to have done their officials’ eye monitoring in a real-life game situation.
“What’s a little funny is that we often hear that the ref ‘should’ve seen it,’ and now we can tell that they really have or should’ve seen it," Hansson said.
But what you see and what you pay attention to are two different things. There are so many other variables. Positioning, stress, fatigue, to name a few.
“We’ve managed to bust one myth. Coaches often tell players to turn their heads to scan the ice, but we can prove that the more you move your head the less you see,” Hansson said.
A better way is to look, take a snapshot, and have another look.
The study has also shown how differently referees work if they have a partner on the ice.
“With two referees, their vision is more horizontal as they trust their partner to make calls outside their vision. A lone referee will have a more circular field of vision. That’s important for us when we develop new referees, we can guide them better to take the next step,” Hansson said.
Hansson and his team have a lot of data to work with. Now their next step is to figure how they can help the referees in the future.
Because hindsight is, unfortunately for the officials, always 20/20.
A referee can only call what he or she sees. But anyone who’s ever seen a hockey game knows that sometimes the on-ice officials miss calls, even though everyone else in the arena seems to have seen what happened.
As part of the continual development of officials, the IIHF has conducted studies on the referees’ vision. What do they actually see, and how do they make observations on the ice when things happen fast?
“We knew how fast officials can skate or run, or how much they could squat at the gym, so we wanted to go a little deeper and see if we had missed some part of the equation,” said Joel Hansson, Officiating Development Manager at the IIHF.
One of the studies the IIHF looked at was what makes great football players great and learned that Lionel Messi, for example, made much more frequent eye and head movements, to scan the field, than players that weren’t at his level. Other, similar studies have also highlighted the importance of scanning.
Together with specialist Lee Waters, the IIHF has provided the on-ice officials with special glasses in four junior tournaments – most lately at the IIHF Ice Hockey U18 Women's World Championship in Finland. The glasses have two cameras: one records the game events, or what the referees see, and the other the ref’s eyes.
“A red dot shows where the referee’s eyes are focused, and the size of the dot tells us how fully they’re focused on, say, a puck in the corner,” Hansson said.
“And we can tell that over the course of a tournament the focus changes. Early on, everyone’s very alert and focused, but as the tournament progresses, fatigue or stress affects them.”
The pressure on the cognitive brain also increases, which can lead to more decisions made on gut instinct, or by the reptile brain, if you will.
That knowledge can help with the officials’ game preparation and load management, according to Hansson. Maybe it’s best to give an official day off to make sure he or she is better prepared for the next game.
“We know they’re in shape, eat well, sleep well, but we also know they’re on the ice for the full 60 minutes, and have to make many, quick decisions," Hansson said. "One thing we’re looking into is how to, firstly, relax after a game, and secondly, warm up for a new game.”
Some people watch TV after a game, others read, or maybe play a video game, all activities in which the eyes are fed new stimuli.
“What we’re looking for are ways to help the officials to find new patterns and tools that they can use, for example, when warming up, especially their eyes," Hansson said. "We’ve looked into what is being done in Formula 1 racing, how they work with reaction times and so on.”
All this just to help officials to make better decisions.
The IIHF is the only sport to have done their officials’ eye monitoring in a real-life game situation.
“What’s a little funny is that we often hear that the ref ‘should’ve seen it,’ and now we can tell that they really have or should’ve seen it," Hansson said.
But what you see and what you pay attention to are two different things. There are so many other variables. Positioning, stress, fatigue, to name a few.
“We’ve managed to bust one myth. Coaches often tell players to turn their heads to scan the ice, but we can prove that the more you move your head the less you see,” Hansson said.
A better way is to look, take a snapshot, and have another look.
The study has also shown how differently referees work if they have a partner on the ice.
“With two referees, their vision is more horizontal as they trust their partner to make calls outside their vision. A lone referee will have a more circular field of vision. That’s important for us when we develop new referees, we can guide them better to take the next step,” Hansson said.
Hansson and his team have a lot of data to work with. Now their next step is to figure how they can help the referees in the future.
Because hindsight is, unfortunately for the officials, always 20/20.