Sealed in a motorcar one is protected largely from the hazards of the outside world. In particular, insects either bounce off or come to a sticky end on the windscreen or other parts of the front end of the vehicle. Not so on a bicycle.
On the road between Earlswood and Hockley Heath the other day I was minding my own business and sailing along at just under 25 mph, when a bee chose to land on my forehead, between helmet and shades. I shook my head but the bee decided to take shelter, behind the spectacles! It crept up over the cheekbone and I closed my right eye to let it crawl across over my nose. Quickly shutting my left eye and opening my right, the bee strolled over to my left temple. There was nowhere convenient to slide off the road to a stop for a hundred or so yards. The bee then decided to do a reverse traverse and, in between synchronised blinking, I spotted a driveway. Off and in and pulled to a stop. Relief! As soon as I was stationary the bee flew off and no damage done to it or me!
Apian shade
So, it is always worth wearing spectacles when out cycling. If not just to protect bees from the wind then certainly to protect one’s eyes from other insects and any stray detritus which might be carried on the wind.