Official rules: ridiculously stylish eyewear

13. It should go without saying that ridiculously stylish eyewear should not be worn at any time. Eyewear should be cheap clear glasses to avoid rain and road-dirt, except when the sky is cloudless (generally only in July and September). Glasses may be worn under helmet straps and headband or cycle cap, to avoid losing them.

Official rules of the Scottish Cyclist: full list
Official rules of the Euro Cyclist

Not sure this comes under ‘stylish’ or not
Festina retro cycling glasses and glove