How does vision impact Paralympic performance? Waterloo Optometry researcher sets out to measure visual impairment in Paralympic skiers

Sunday, April 1, 2018

The women's visually impaired Super-G event at the 2013 IPC Alpine World Championships in La Molina, Spain. Henrieta Farkasova and guide Natalia Subtrova. Photo credit: Laura Hale.

The women's visually impaired Super-G event at the 2013 IPC Alpine World Championships in La Molina, Spain. Henrieta Farkasova and guide Natalia Subtrova. Photo credit: Laura Hale.

Imagine standing at the top of a double black diamond ski run, descending 3,000 feet over bumpy and icy terrain, reaching speeds of 80 mph. Now imagine doing all of this blind.

"If you’ve ever watched the Paralympics or have been lucky enough to know a Para athlete, then you’ll understand the strength of these individuals and the importance of sport in their lives,” says Kristine Dalton, an assistant professor in the School of Optometry and Vision Science and founder of the Sports Vision Clinic at the University of Waterloo. “In Para sport, making sure that athletes with similar impairments compete against each other - whether it’s a physical, mental or visual impairment - keeps competition fair."

Professor Dalton is one of the experts working with the International Paralympic Committee (IPC) to help redevelop classification rules for visually impaired athletes that reflect the unique visual demands of each Paralympic sport.The women's visually impaired Super-G event at the 2013 IPC Alpine World Championships in La Molina, Spain. Henrieta Farkasova and guide Natalia Subtrova. Photo credit: Laura Hale. The IPC has already started developing sport-specific classification systems for physical and intellectual impairments,” said Dalton. “And the work on visual impairment has been making good progress since it started in 2015.

Currently, she is focusing her efforts on both Alpine (downhill) and Nordic (cross-country) skiing. Dalton measures the functional impact of vision impairments on an athlete’s performance under real-world conditions in Alpine and Nordic skiing, conditions which are very different from those of rowers, runners, swimmers, and judokas. 

"In the case of (Alpine or Nordic) skiing, natural lighting conditions can vary dramatically from the start to finish of a race,” says Dalton. “If you’re glare sensitive, then moving from a section of a course shaded by trees into the sun can make it difficult to see important details on the course, like the position of the gates or changes in the snow conditions, especially when moving at high speeds."

To account for the unique aspects of skiing in her research, Dalton is going beyond the standard vision tests and measuring a range of functional vision parameters, including dynamic visual acuity, motion perception, contrast sensitivity, and glare sensitivity in both Para Alpine and Para Nordic skiers; she is then matching these results with individual athlete’s performance in each sport in order to begin understanding the impact of visual impairments on skiing performance.

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Visual impairment is more complex than simply the complete absence of sight. There are a number of conditions that can hinder someone’s vision.  As a result, visual impairments can reduce one’s ability to see details or colours, track moving objects, judge depth and distances, and / or adjust their focus to see in poor or unpredictable lighting conditions (low contrast or glare).

Despite the complexity vision poses as an impairment, there are only three classes for Paralympic competition at present: B1, B2, or B3. Athletes who compete in these groups are classified based on their ability to read an eye chart (static visual acuity) and the extent of their peripheral vision (visual field) in the better eye. The current classes cover impairments ranging from total blindness (B1) to partial sight (B2, B3), and the classes are the same regardless of what sport the athlete plays.

Once Daltons’ research is complete, the International Paralympic Committee will review the data and use this knowledge to make evidence-based recommendations for Alpine and Nordic skiing to tailor and redefine the current classification system for these sports.

The 2018 Winter Paralympic Games took place in PyeongChang March 9-18. Canada sent a record 55 athletes who won 28 medals – Team Canada’s best podium finish ever at a Winter Paralympics Games.