A buyer in Osaka sent back three samples of a soft glasses pouch with a photograph of a bent temple arm. The pouch had been packed inside a carton of 200 units, stacked four high, for eleven days. Whatever we proposed had to survive that stack, which is a crush problem rather than a drop problem, and it is the reason most soft pouches fail.
Eyewear needs a softer shell than tools. We build glasses cases at Shore C 50-58 with a 3-4 mm wall, which is enough to take a 1.0 m drop onto concrete and still let the lid flex instead of transmitting the load to the frame. Go much harder and the shell stops absorbing and starts transferring, and the nose bridge is what pays for it. A molded shell also keeps its shape when something heavy is set on top of it inside a bag.
The hinge line is where cheap cases fail
Compression molding lets us form the body and lid in one piece with a live hinge along the back, so there is no stitched seam running past the lens. Stitching is the usual culprit behind scratched lenses: the thread sits proud, the lining wears through, and the lens ends up riding against a hard edge. Inside we use velvet or flocked lining chosen as much for lint as for feel, because loose fibre on a coated lens is its own complaint. Every lining gets a dry cloth rub test before the first bulk run.
What we actually test on eyewear
Static crush is the one that matters most. We load the lid with roughly 40 kgf spread across the face for a minute and check that the temple arms inside come out straight. After that, a 1.0 m drop on six faces, about 5,000 zipper cycles, and a closure fatigue check on magnetic snap versions, since a snap loses holding force long before a zipper does. Oversized sport frames and shield sunglasses have pushed internal clearances up over the last two years, so we now start at about 150 mm of clear width and adjust from the frame drawing.
Sizing and standards for children's frames
Kids' versions are shorter, get rounded corners, and are tested against EN 71 where the buyer sells into the EU, with California Prop 65 wording when they go to the US. RoHS and REACH declarations are standard. Cases that carry a spare lens, a cleaning cloth or a small charging cable for audio glasses borrow cavity practice from our cases for electronic accessories, where the same +/-1 mm foam tolerance applies.
The Osaka replacement samples shipped with a 4 mm wall and a wider nose bridge relief cut into the foam. A glasses case is a small part of our full product range, but it generates more revision rounds than almost anything else on the floor, usually over a millimetre of clearance. The mold technician dropped the forming temperature by 5 degC on the second trial and the hinge stopped showing a stress mark along the back.