I’ve had probems with my contacts in very cold weather at night when going down descents at speed. I think the problem is that on long descents such as the ClimachX final descent, I don’t blink very much. On two different occasions I have attempted to blink about half way down and found that it is as though the contact lens is twice as thick as normal and does not allow my eyelid to pass over it. Feels very very weird. The first time repeated attempts at blinking finally worked, but the second time the contact lens pinged out of my eye scratching the surface as it did so :o(. Pretty painful. I now force myself to blink lots on descents at night in the winter.
