An optical error

Here's a little thread that has an optical angle and will also be of interest to blog watchers of the ironman blog. Like most people in the UK down here is Surrey we woke up to a good covering of snow. realising that the roads and rail would be a nightmare I decided that an off road cycle to work would be the best way to get in. On these dull mornings I have been wearing some Oakley Activated by Transitions with Persimmon to black Iridium lenses. these are great for flat light but also protect you eye while on the bike. As it was still snowing I decided that it would be best to leave the specs at home as they would just get covered. What a mistake, I was half blinded all the way by icy rain and snow in the eyes plus all the slush being thrown up from the ground. I'll try and post a picture later.