Switzerland goalkeepers wear battery-powered Japanese glasses to boost reflexes for England tie

Switzerland goalkeeper Yann Sommer has been preparing to face Jude Bellingham and Harry Kane by training in futuristic sunglasses specially designed to sharpen his reflexes.

Inter Milan star Sommer has been photographed wearing battery-powered specs that create a slow-motion effect when a ball is struck, with the aim of improving a player’s reaction speed.

The £350-plus design from Japanese company VisionUp was also worn by understudy Gregor Kobel while the pair trained on Friday for Switzerland’s European Championship quarter-final against England the following evening.

The glasses were used by the duo throughout their country’s Euro 2020 campaign three years ago, which saw Sommer famously save from Kylian Mbappe during their last-16 penalty-shootout triumph against France.

The specs made a further appearance during their run to the last 16 of the World Cup in Qatar, when they were thrashed 6-1 by Portugal.

Athletes in various other sports, including tennis and baseball, have also used the glasses during training sessions.

VisionUp says on its website: “You can easily improve brain processing speed and visual ability, such as kinetic visual acuity, dynamic visual acuity, peripheral vision, depth perception and hand-eye coordination.

“You can thus obtain better athletic performance. VisionUp are useful not only to athletes but also young or elderly people.”

The glasses are just one example of the marginal gains teams are seeking to give them an edge over their opponents at Euro 2024.

England are among those whose players have been drinking pickle juice in order to ward off the effects of cramp.

Containing sodium, potassium and vinegar, the drink triggers a reflex in the mouth, sending a signal to stop muscles from cramping up.

It is also said to improve gut health with antioxidants, help control blood sugar levels and promote fresh-smelling breath due to it killing bacteria which reproduces in the mouth.