Today’s invention is sunglasses with segmented, overlapping lenses.
Each segment is attached to a pivot at the nosepiece, allowing them to slide over each other, covering some fraction of one side of the face. This would allow a range of options for eye protection: either lots of stray light to be excluded or direct beams to be dimmed.
The triangular segments would have different-strength filters, so that many different combinations of colour, density etc could be selected.
It might even be possible to have the motion of the lenses powered via a small hydraulic reservoir and remote switch, so that these glasses could also take on a social signalling role.