Colour vision at very high altitude

The goal of our study was to evaluate colour vision during high-altitude mo untain climbing without supplemental oxygen. Two Himalayan expeditions were invited to test their colour perception at both the highest possible altit ude and on the largest possible number of subjects. The panel desaturated D 15 was used, because only a simple test could be transported to those altit udes. There were 2 evaluations (i.e., 4 eyes) at 7,000 m during the first e xpedition in 1997 and 3 evaluations (i.e., 6 eyes) at 6,500 m during the se cond expedition in 1998. The results were in perfect agreement and can be c onsidered practically normal for all 5 mountain climbers. (C) 2000 John Wil ey & Sons, Inc.