[The Antiyuppie]

Auto dimming welding helmets won’t work. They use solar cells to power an LCD shutter for broad spectrum darkness, mostly for comfort. The glass itself filters out ultraviolet and infrared. A Single green laser won’t power the solar cells.

It might be possible to make a laser detector that would operate the shutter fast enough to prevent (much) damage. Having it work fast enough and clear/dark enough to be wearable and effective, probably very tough.

[freeandfreezing]

Thanks for the more serious reply. You are correct, getting a fast response time to the targeted narrow band laser illumination is hard. Glasses with fixed narrow band filtration are a better bet.

That said a good project would be an automatic localizer for the source attached to a high capacity paint ball or rubber pellet gun.

Useful reading on the topic:

General Safety Guidelines

Sensor Protection

A vendor of laser safety glasses

The vendor sells glasses specifically made to protect against attacks using common green lasers in the category "Laser Strike Glasses"