Why don't we do it in the road?

New random health problem alert.
I noticed my left eye was blurred at the weekend (it's still blurred, it was the weekend that the noticing occurred), I could see but reading, at any distance, was difficult. My immediate worry was not my health, but the £350 I recently splashed out on two pairs of varifocals! I'm not going through that again (and I obviously can't afford to).
Anyway, it's getting a little better, I'm putting it down to fatigue, I really really hope that's all it is.