Post-2012 Gear: Adjustable Specs

I think in Australia the number of adults needing spectacles/contacts/laser is about 50%, which means for those like me who haven't dared have laser surgery yet, after a 2012 cataclysm our contacts and specs will be very, very important to keep safe. Once they are gone/damaged, replacing them might be impossible.

Whether they are for personal use, or trade/barter, stocking up on adjustable specs might be a smart move. That's right, adjustable:

They consist of clear membranes filled with silicon oil, protected by plastic discs. The wearer can adjust the amount of oil in the lenses using a dial fitted to a syringe on the arms of the glasses. Changing the amount of oil in the lenses changes their curvature, which alters their strength.

When someone has adjusted the lenses to suit their vision, the lenses are sealed with a valve and the syringes removed, giving near-instant glasses with no need for an optometrist.

30,000 of these have been distributed in Africa, with a manufacturing cost of $19 each. They aren't pretty, but they are pretty cheap. A box of these would be a good investment for any bunker. Story at CNN. Official site is the Centre for Vision in the Developing World