This is the quickest way to ruin your helmet's aero performance and everybody does it, but here's a free fix

When you remove your sunglasses while cycling, avoid slotting them into the vents of your helmet for aerodynamic reasons, even though many riders, including pro riders, tend to do so.

Brands are aware of the need for eyewear storage while riding, hence many helmets now come with dedicated eyewear docks or features that keep sunglasses secure, ensuring they don't compromise aerodynamics.

Read at cyclingnews.com