It's also the German obsession with sticking to your narrow field/specialism.
The whole thing was just a bit odd as I went with preconceived ideas about what would happen:
1. Taken into a back room and have a proper sight test, including Glaucoma puffer, light shining in eye to detect retinal cancer, circles clearer in the red or the blue, wearing weird spec frames with lots of little lenses in, 'which line can you read when you hold this near your face' etc etc. Asking me about my Lasik surgery and when was it etc. General chat about my health, whether I do work with computer screens, how I find my sight etc etc
2. Aha, your prescription has changed minutely so let us sell you some expensive glasses
3. Here's some paperwork with your prescription on it
4. Let's clean and adjust your current specs
What I got was
1. Boat on beach
2. You don't need new glasses
3. Here are your glasses cleaned
Mind you, I paid nothing for it, but for a shop trying to sell glasses they could have tried a bit harder as I wanted some new frames anyway...