Ahead of the London 2012 Paralympic Sailing Competition sailors who have a vision impairment are tested by IPC vision classifiers with correspondence between IFDS to ensure the correct classification is assigned.
There are varying degrees of visual impairment and athletes are tested on their visual acuity and depending on the type of vision they possess they are classified accordingly.
The schedule for those who need to be classified is available here.
Watch back highlights from World Sailing's 2017 World Cup Series Miami. Held in Coconut Grove, Miami, USA from 24-29 January 2017 the World Cup saw more than 400 sailors from 44 nations gather as the trail to Tokyo 2020 commenced.
Find out who took the honours across the 470, Laser, Laser Radial, RS:X, 49er, 49erFX, Nacra 17 and Finn fleets after six days of racing on Biscayne Bay.