Commuters and other cyclists who need to ride at particular times are most vulnerable to the caprices of the weather. Spectacle wearers are hardest hit if they need to use their bicycle in the rain. This group need a device to mitigate the worst effect of rain on their eyewear.
What is needed is a 'Commuter Super-Visor' if you will, to keep their eyeglasses dry (or nearly dry), free of fog and provide sight lines which will allow safe riding. It is to this requirement that I address this document.
Keeping spectacles dry in the rain requires protecting them from direct impact by raindrops - a cover above the glasses works for this. My device fixes to the rider's helmet by a silicone rubber band in place of, or in addition to, the existing brow peak to provide shelter from water coming from above. It slopes down rather than extending straight out to enhance this mechanical protection from the elements. It extends outward around 12 cm before turning downward as described next.
Keeping oblique and splashed drops from settling on the eyeglass lenses requires further mechanical protection. For this purpose my device has a 'skirt' of the transparent material (currently VIVEK, but if produced, probably polycarbonate) from which it is made, extending downward from its outer perimeter. This skirt extends back close to the helmet to reduce the effect of side and splashed water spray.
The device reduces or eliminates fogging of the glasses by being open to the elements below, and by providing a relatively large volume in which fresh air circulation can take place.
The downward slope of the device's sightlines allow the rider to navigate normally by looking downward below the lower periphery of the skirt. The view of the road is unimpeded and of a fairly normal extent forward. The transparency of the skirt and the top mean that traffic lights, taillights and headlights can be seen (albeit in a rain blurred way) through both the skirt and the top, and, where and when fuller cognisance needs to be taken of a potential danger, the rider can examine it through dry eyeglass lenses by tipping her head back enough to see the it directly. The amount of tip is not uncomfortable.
I have been testing a prototype of this device for some 12 months now, and it does indeed do the things I have outlined above.