When was the para-alpine skiing classification system developed?
Para-alpine skiing classification
In 2010, there were three vision impaired classifications, B1, B2 and B3.  These classifications based on a gradient with B1 being the most severe and B3 being the least severe, with B3 skiers having vision around 2/60 to 6/60.[10] Beyond the level of vision impairment, research done at the Central Institute on Employment Abilities of the Handicapped in Moscow has found differences in functional capabilities based on differences in visual acuity, which plays a significant role in skiing.[11]