I left the training room too eager to go to gemba today and forgot to put on my safety glasses. Within two minutes one of the safety coordinators on the shop floor stopped me and sent me back to get them. Kudos to the management of this company for instilling this level of safety awareness in their people.
In order to keep kaizen going over decades, you need to be dissatisfied. In order to be dissatisfied you need have high ideals. The definition of "ideal" in TPS includes safety. A product, process or service should be safe, first and foremost. All kaizen should improve safety.
Why do most American factories require people in the factory to wear safety glasses? Perhaps it has something to do with Ralph Nader. The obvious answer is that the safety glasses protect peoples' eyes from injury caused by flying debris. Why do we have flying debris? Safety is not built into the process.
The Japanese consultants I worked with always puzzled at why American and European factories had such inadequate guarding at the source of the debris. They used to say that safety glasses are a sign of unsafe processes. I think of safety glasses as an sign of a process that is far from ideal, just like inventory is a sign of a lack of flow or forklifts are a sign of disconnected processes.
I have not been to all Japanese factories, but I have never seen safety glasses worn in the factories I have visited. In Japan they do wear caps, called "safety caps". These caps are thinner than baseball caps, so presumably the flying debris in Japanese factories is quite flimsy.
There is an interesting story about Taiichi Ohno. In the early days of implementing the Toyota Production System at Toyota, one of the workers in the factory who was not so eager to change threatened Ohno with a hammer. From then on, Ohno did not wear a safety cap when he went to the gemba. Part of this was to show people that he was putting his life on the line to make TPS succeed. Part of it may have been that he saw how silly it was to wear the safety cap in an unsafe workplace.
Safety glasses protect your eyes, but they can also make your unsafe processes less visible.