Smart goggles that help swimmers log lengths have been designed by a UK engineering student.
The lap times appear on the goggle lens
The Inview goggles display a lap count and time elapsed on their lenses so swimmers can track their progress.
Invented by industrial design student Katie Williams, the goggles use an in-built compass to spot when swimmers complete lengths.
Ms Williams said the goggles would let swimmers concentrate on improving their strokes rather than count laps.
Ms Williams said the idea for the Inview goggles came out of her past experiences as a lifeguard at her local swimming pool.
Many keen swimmers rely on a wristwatch or wall-mounted pace clock to keep track of lap times but both change the way that people swim.
"If they have a watch on a lot of swimmers will move their left arm differently, just to see how fast they are going," she said. "It's wasting energy for them really."
Many swimmers also found it difficult to keep track of how many lengths they had swum, especially if they were doing a lot of them or were concentrating on getting a stroke perfect, she said.
"I never knew how many I'd swum," said Ms Williams.
The Inview goggles rely on a compass that orients itself when a swimmer first enters the pool. This compass spots when a swimmer changes direction and logs a lap.
The Inview goggles were designed and built for a third-year project on an Industrial Design course at Brunel University.
The prototype electronics package housing compass and lap counter are the size of a small stone, and would be a bit uncomfortable to swim with, said Ms Williams.
However, the electronics on a finished product would be no bigger than a 50 pence piece and would sit unobtrusively on the goggle's rear strap.